KR102220141B1 - Thermosetting adhesive composition, laminated film having the cured product of the composition, and printed wiring board having the laminated film - Google Patents

Abstract

A thermosetting adhesive composition, a laminated film containing a cured product thereof, and a printed wiring board employing the laminated film are disclosed. The disclosed thermosetting adhesive composition includes 100 parts by weight of a modified polyimide resin that is a reactant of a monomer group including an aromatic tetracarboxylic anhydride and a diamine, a main chain including an alkylene chain having 10 or more carbon atoms, and an alkyl group bonded to the alkylene chain. 5 to 20 parts by weight of a long-chain alkyl bismaleimide resin having a side chain, and 3 to 10 parts by weight of an epoxy resin.

Description

A thermosetting adhesive composition, a laminated film including a cured product thereof, and a printed wiring board employing the laminated film TECHNICAL FIELD [0002] A thermosetting adhesive composition, laminated film having the cured product of the composition, and printed wiring board having the laminated film

A thermosetting adhesive composition, a laminated film containing a cured product thereof, and a printed wiring board employing the laminated film are disclosed. More specifically, a thermosetting adhesive composition comprising a modified polyimide resin, a long-chain alkylbismaleimide resin, and an epoxy resin as main components, a laminated film comprising a cured product thereof, and a printed wiring board employing the laminated film are disclosed.

In recent years, the need for a printed circuit board (PCB) that is easy to embed in a narrower space is increasing according to the trend of integration, miniaturization, thin film, high density and high bending of electronic products. Accordingly, a flexible printed circuit board (FPCB), which is capable of miniaturization and high density, and has repetitive flexibility, has been developed. As the usage of FPCBs increases rapidly due to technological developments such as mobile phones, DVDs, digital cameras or PDPs, the demand for such FPCBs is increasing even more.

In recent years, in the field of flexible printed circuit board technology (FPCB), demand for high-speed and large-capacity transmission signals is increasing, and thus, high-frequency transmission signals are in progress. Since the signal loss is relatively large in the high frequency region compared to the previous one, the characteristics of suppressing transmission loss are also required in the FPCB, and excellent electrical properties, low dielectric constant and excellent in the related base film and the adhesive applied to such base film. It is a situation in which anti-migration characteristics and the like are required.

As an adhesive composition used in a base film for manufacturing a flexible printed circuit board as satisfying these requirements, various combinations selected from thermosetting resins, thermoplastic resins, high strength and highly flexible elastomers have been generally used.

Typical adhesive compositions include a blend of an epoxy resin and an acrylonitrile butadiene rubber (hereinafter referred to as'NBR'), a blend of an epoxy resin and a polyester, and a blend of an epoxy resin and an acrylic resin. Among them, the adhesive composition, which is a blend of an epoxy resin and NBR, is most widely used because it has an adhesive strength and heat resistance at a level suitable for the manufacture of FPCB.

However, since the conventional adhesive composition has many functional groups such as hydroxyl group, carboxyl group and nitrile group, the adhesion to the base film can be improved, but on the contrary, both dielectric constant and dielectric dissipation factor tend to be increased.

In addition, a large amount of ionic impurities are contained in the NBR, which is mainly used, and since these impurities are a major factor causing ion migration, it is inevitable to use expensive, high-purity products that have been generally purified.

One embodiment of the present invention provides a thermosetting adhesive composition comprising a modified polyimide resin, a long chain alkyl bismaleimide resin, and an epoxy resin as main components.

Another embodiment of the present invention provides a laminated film comprising a cured product of the composition for producing a thermosetting resin.

Another embodiment of the present invention provides a printed wiring board employing the laminated film.

One aspect of the present invention,

100 parts by weight of a modified polyimide resin that is a reactant of a monomer group containing an aromatic tetracarboxylic anhydride and a diamine;

5 to 20 parts by weight of a long-chain alkylbismaleimide resin having a main chain including an alkylene chain having 10 or more carbon atoms and a side chain including an alkyl group bonded to the alkylene chain; And

It provides a thermosetting adhesive composition comprising 3 to 10 parts by weight of an epoxy resin.

The aromatic tetracarboxylic anhydride may be represented by the following Formula 1:

[Formula 1]

In the formula, X is a single bond, -SO ₂ -, -CO-, -O-, -OC ₆ H ₄ -C(CH ₃ ) ₂ -C ₆ H ₄ -O- or -COO-X ¹ -OCO- (X ¹ represents -(CH ₂ ) ₁ -(l=1 to 20) or -H ₂ C-HC(-OC(=O)-CH ₃ )-CH ₂ -).

The diamine may be one obtained by substituting all carboxyl groups in a dimer acid of an unsaturated fatty acid, a trimer acid of an unsaturated fatty acid, or a mixture thereof with a primary amino group.

The modified polyimide resin may include polydimethylsiloxane.

The long-chain alkylbismaleimide resin may include a maleimide group, a divalent group having at least two imide bonds, and a compound having a saturated or unsaturated divalent hydrocarbon group.

The epoxy compound may include a polyfunctional epoxy resin having three or more epoxy groups.

The thermosetting adhesive composition may further include 2 parts by weight or less of a reaction initiator based on 100 parts by weight of the modified polyimide resin.

The thermosetting adhesive composition may further include 2 parts by weight or less of a curing accelerator based on 100 parts by weight of the modified polyimide resin.

The monomer group may further include diaminopolysiloxane.

The thermosetting adhesive composition further includes an organic solvent, and the content of the organic solvent may be 40 to 90 parts by weight based on 100 parts by weight of the total weight of the thermosetting adhesive composition including the organic solvent.

Another aspect of the invention,

Base film; And

Including an adhesive layer disposed on the base film,

The adhesive layer provides a laminated film comprising a cured product of the thermosetting adhesive composition.

The laminated film may be a coverlay film.

Another aspect of the invention,

It provides a printed wiring board including the laminated film.

When a voltage of 100V is applied under 85% relative humidity and 85°C temperature conditions, the printed wiring board may have a migration resistance that does not cause a short circuit within 1,000 hr.

The printed wiring board may be a flexible printed circuit board.

The thermosetting adhesive composition according to the embodiment of the present invention can provide a laminated film and a printed wiring board having low dielectric constant, low dielectric loss factor, excellent migration resistance, excellent adhesiveness (peel strength) and excellent heat resistance.

In addition, the printed wiring board according to an embodiment of the present invention can provide high electrical reliability when applied to a network-related electronic device such as a mobile communication device and its base station equipment represented by a smart phone or a mobile phone.

1 is a cross-sectional view schematically showing a laminated film according to an embodiment of the present invention.
2 is a schematic cross-sectional view of a printed wiring board according to an embodiment of the present invention.

Hereinafter, a thermosetting adhesive composition according to an embodiment of the present invention will be described in detail.

The thermosetting adhesive composition according to an embodiment of the present invention includes 100 parts by weight of a modified polyimide resin, 5 to 20 parts by weight of a long-chain alkyl bismaleimide resin, and 3 to 10 parts by weight of an epoxy resin.

When the contents of the modified polyimide resin, the long-chain alkyl bismaleimide resin, and the epoxy resin are outside the above ranges, low dielectric constant, low dielectric loss rate, excellent migration resistance, excellent adhesion (peel strength) and excellent heat resistance A laminated film, a metal foil laminate, and a printed wiring board that do not satisfy at least one of the characteristics may be obtained.

The modified polyimide resin may be a reactant of a monomer group including an aromatic tetracarboxylic anhydride and a diamine.

The aromatic tetracarboxylic anhydride may be represented by the following Formula 1:

[Formula 1]

In the formula, X is a single bond, -SO ₂ -, -CO-, -O-, -OC ₆ H ₄ -C(CH ₃ ) ₂ -C ₆ H ₄ -O- or -COO-X ¹ -OCO- (X ¹ represents -(CH ₂ ) ₁ -(l=1 to 20) or -H ₂ C-HC(-OC(=O)-CH ₃ )-CH ₂ -).

Specifically, the aromatic tetracarboxylic anhydride is pyromellitic dianhydride, 4, 4'-oxydiphthalic dianhydride, 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride, 3, 3 ', 4, 4'-diphenyl ether tetracarboxylic dianhydride, 3, 3', 4, 4'-diphenyl sulfone tetracarboxylic dianhydride, 1, 2, 3, 4-benzenetetracarboxylic acid Anhydride, 1, 4, 5, 8-naphthalenetetracarboxylic anhydride, 2, 3, 6, 7-naphthalenetetracarboxylic anhydride, 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride , 2, 2', 3, 3'-biphenyltetracarboxylic dianhydride, 2, 3, 3', 4'-biphenyltetracarboxylic dianhydride, 2, 3, 3', 4'-benzo Phenonetetracarboxylic dianhydride, 2, 3, 3', 4'-diphenylethertetracarboxylic dianhydride, 2, 3, 3', 4'-diphenylsulfonetetracarboxylic dianhydride, 2, 2-bis (3, 3', 4, 4'-tetracarboxyphenyl) tetrafluoropropane dianhydride, 2, 2'-bis (3, 4-dicarboxyphenoxyphenyl) sulfone dianhydride, 2, 2- Bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 4, 4'-[propane-2, 2-diylbis(1, 4 -Phenyleneoxy)] diphthalic acid dianhydride or a combination thereof.

The diamine is a dimer acid (refer to Japanese Laid-Open Patent Publication No. 1997-12712), which is a dimer of an unsaturated fatty acid (e.g., oleic acid), and a trimer acid (manufactured by Japanese Unexamined Patent Publication), a trimer of an unsaturated fatty acid (e.g. 2013-505345) or all carboxyl groups in a mixture thereof may be substituted with a primary amino group.

Specifically, the diamine may include at least one compound represented by Formulas 2 to 8 below.

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

In each of the above formulas, m+n=6 to 17, p+q=8 to 19, the broken line means a carbon-carbon single bond or a carbon-carbon double bond, and R is an ethylene group (-CH ₂ CH ₂ -) or It means a tenylene group (-CH=CH-).

As a commercial item of the said diamine, for example, Basamine 551 (manufactured by BASF Japan Co., Ltd.), Basamine 552 (manufactured by Kognix Japan; Hydrogenated product of Vasamine 551), PRIAMINE 1075, PRIAMINE 1074 (all Kuroda Japan Co., Ltd. product) etc. are mentioned. In addition, the components of these commercially available products are usually about 95 to 98% by mass of the component derived from dimer acid, and the component derived from the trimer acid is usually contained in the range of 2% by mass or less.

As another commercial item of the said diamine, PRIAMINE 1071 (Kuroda Japan Co., Ltd. product) etc. are mentioned. In addition, as for the component of this commercial item, the component derived from trimer acid is usually about 15 to 20% by mass, and the balance contains more than 80% by mass of the component derived from dimer acid.

The content of the component derived from dimer acid in the diamine may be 30 mol% or more.

The monomer group may further include diaminopolysiloxane.

When the diaminopolysiloxane is included, the flexibility of the adhesive layer prepared from the thermosetting adhesive composition and the surface smoothness of the coating film become good, so that the adhesion of the adhesive layer to the metal foil can be improved.

The diaminopolysiloxane is α, ω-bis (2-aminoethyl) polydimethylsiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, α, ω-bis (4-aminobutyl) polydimethylsiloxane, α,ω-bis(5-aminopentyl)polydimethylsiloxane, α,ω-bis[3-(2-aminophenyl)propyl]polydimethylsiloxane, α,ω-bis[3-(4-aminophenyl)propyl] ] Polydimethylsiloxane, 1, 3-bis(3-aminopropyl) tetramethyldisiloxane, 1, 3-bis(4-aminobutyl) tetramethyldisiloxane, or a combination thereof.

The content of the diaminopolysiloxane in the diamine may be 0.1 to 10 mol%.

The modified polyimide resin may include polydimethylsiloxane.

The long-chain alkyl bismaleimide resin serves to sufficiently lower the dielectric constant and dielectric loss factor of the completely cured product of the thermosetting adhesive composition.

The long-chain alkylbismaleimide resin may include a maleimide group, a divalent group having at least two imide bonds, and a compound having a saturated or unsaturated divalent hydrocarbon group.

The long-chain alkyl bismaleimide resin has a thermosetting part by two or more maleimides in one molecule, and a low-dielectric property expression part by an alkylene chain, and the alkylene chain has a side chain instead of a straight chain. A predetermined dielectric property is obtained in proportion to the blending amount. The maleimide group may be bonded to an aromatic ring or to an aliphatic chain, but from the viewpoint of dielectric properties, it is preferable that it is bonded to an aliphatic chain.

The main chain constituting the long-chain alkylbismaleimide resin may include an alkylene chain having 10 to 102 carbon atoms, an alkylene chain having 12 to 52 carbon atoms, and an alkylene chain having 14 to 22 carbon atoms. In addition, the side chain may include an alkyl group having 2 to 50 carbon atoms, an alkyl group having 3 to 25 carbon atoms, and an alkyl group having 4 to 10 carbon atoms.

The lower limit of the weight average molecular weight (Mw) of the long-chain alkyl bismaleimide resin may be 500 or more, 1000 or more, 1500 or more, or 1700, and the upper limit of Mw of the long-chain alkyl bismaleimide resin is 10,000 or less, 9,000 or less, 7,000 It may be less than or equal to 5,000. From the viewpoint of handleability, fluidity and circuit embedding (Mw of the long-chain alkylbismaleimide resin may be 500 to 10,000, 1,000 to 9,000, 1,500 to 9,000, 1,500 to 7,000, 1,700 to 5,000.

The long-chain alkylbismaleimide resin may be represented by the following formula (9).

[Formula 9]

In the formula, R and Q each represent an independent divalent organic group. Specifically, R represents an alkylene group having a branch of 8 to 100 carbon atoms, an alkylene group having a branch of 10 to 70 carbon atoms, an alkylene group having a branch of 15 to 50 carbon atoms, and Q is an aromatic, for example, anhydrous pyrolysis. Represents a group in which two acid anhydride groups have been removed from melitic acid, and n represents an integer of 1 to 10.

As the long-chain alkyl bismaleimide resin, a commercially available compound can be used. As a commercially available compound, a product made by Designer Molecules Inc. is mentioned, for example, specifically, BMI-1500, BMI-1700, BMI-3000, BMI-5000, BMI-9000 (all brand names), etc. Can be mentioned. From the viewpoint of obtaining better high-frequency characteristics, it is more preferable to use BMI-3000 as the long-chain alkylbismaleimide resin.

If the content of the long-chain alkyl bismaleimide resin is less than 5 parts by weight based on 100 parts by weight of the modified polyimide resin, the effect of lowering the dielectric constant is insignificant. There is a problem of lowering.

The epoxy resin may include a polyfunctional epoxy compound having three or more epoxy groups.

For example, the epoxy resin is a phenol novolak type epoxy compound, a cresol novolak type epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a hydrogenated bisphenol A type epoxy compound, a hydrogenated bisphenol F Type epoxy compound, stilbene type epoxy compound, triazine skeleton-containing epoxy compound, fluorene skeleton-containing epoxy compound, linear aliphatic epoxy compound, alicyclic epoxy compound, glycidylamine type epoxy compound, triphenolmethane type epoxy compound, alkyl modified Triphenolmethane type epoxy compound, biphenyl type epoxy compound, dicyclopentadiene skeleton containing epoxy compound, naphthalene skeleton containing epoxy compound, arylalkylene type epoxy compound, tetraglycidyl xylylenediamine, these epoxy compounds are modified with dimer acid The resulting modified epoxy compound, dimer acid diglycidyl ester, or a combination thereof may be included.

As the epoxy resin, a commercially available compound can be used. Commercially available compounds include, for example, jER603, jER828, jER834, jER807 manufactured by Mitsubishi Chemical Corporation, ST-3000 manufactured by Shinil Iron Chemical Corporation, Seroxide 2021P manufactured by Daicel Chemical Industries, Ltd., YD-172-X75 made by Shinil Iron Chemical Co., Ltd., TETRAD-X made by Mitsubishi Gas Chemical Co., Ltd. are mentioned. Among these, in terms of compatibility of the adhesive of the present invention, low dielectric properties, copper adhesion and solder heat resistance balance, etc., bisphenol A type epoxy compound, bisphenol F type epoxy compound, hydrogenated bisphenol A type epoxy compound and alicyclic epoxy compound At least one selected from the group consisting of is preferable, and triglycidyl-P-aminophenol is preferable.

If the content of the epoxy resin is less than 3 parts by weight based on 100 parts by weight of the modified polyimide resin, there is a problem that heat resistance and adhesion are deteriorated because the modified polyimide resin is not sufficiently cured, and if it exceeds 10 parts by weight, curing An epoxy group that does not participate in the reaction raises the dielectric constant.

The thermosetting adhesive composition may further include 2 parts by weight or less, for example, 0.1 to 2 parts by weight of a reaction initiator based on 100 parts by weight of the modified polyimide resin.

The reaction initiator serves to accelerate the thermal curing of the long-chain alkylbismaleimide resin.

The reaction initiator is not limited thereto, but may include a peroxide.

The peroxide is dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(t-butyl peroxy ) Hexane, bis(tert-butylperoxyisopropyl)benzene, tert-butylhydroperoxide, or combinations thereof.

The thermosetting adhesive composition may further include 2 parts by weight or less, for example, 0.1 to 1 part by weight of a curing accelerator based on 100 parts by weight of the modified polyimide resin.

The curing accelerator serves to form an interpenetrating polymer network in which the modified polyimide resin, the long-chain alkylbismaleimide resin, and the epoxy resin are entangled with each other.

The curing accelerator may include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, triphenylphosphine, or a combination thereof. I can.

The thermosetting adhesive composition may further include an organic solvent for dissolving a solid material such as the modified polyimide resin, the long-chain alkyl bismaleimide resin, and the epoxy resin.

The organic solvent includes alcohols such as methanol, ethanol, butanol, butyl cellosolve, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Aromatic hydrocarbons such as toluene, xylene, and mesitylene; Esters such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate; Nitrogen-containing compounds such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; Or a combination thereof.

The content of the organic solvent may be 40 to 90 parts by weight based on 100 parts by weight of the total weight of the thermosetting adhesive composition including the organic solvent.

The thermosetting adhesive composition contains phosphorus nitrogen such as antioxidants, ion supplements, melamine and its derivatives, phosphorus compounds such as various phosphoric acid esters, and phosphazene compounds within the scope of the present invention, if necessary. It may further include a compound, organic and inorganic components of a silicon-based compound, or a combination thereof.

Adecastaboo PFR, FP-600, FP-700 (above made by ADEKA Co., Ltd.), SP-703, SP-670 (above Shikoku Chemical Industry Co., Ltd.) as a commercial product of phosphorus compounds such as various phosphoric acid esters. Industrial Co., Ltd.), PX-200, CR-733S, CR 20-741 (manufactured by Daihachi Chemical Co., Ltd.), and Exolit OP935 manufactured by Clariant Japan Co., Ltd. Although the amount of the component is not particularly limited, it is usually about 1 to 30 parts by weight based on 100 parts by weight of the resin part.

Since the thermosetting adhesive composition according to an embodiment of the present invention having the above configuration does not contain halogen substances and ionic impurities, the coverlay with improved electrical reliability having low dielectric constant and migration resistance when applied to an electrically insulating substrate Films and adhesive sheets can be provided.

Hereinafter, a laminated film according to an embodiment of the present invention will be described in detail.

A laminated film according to an embodiment of the present invention includes a base film and an adhesive layer disposed on the base film.

The laminated film may be a coverlay film.

The base film may be an insulating film or a release film.

The insulating film may include polyimide, polyester, polyphenylene sulfate, polyester sulfone, polyethyl ketone, aramid, polycarbonate, polyarylate, or a combination thereof.

The thickness of the base film may be 3 to 50 μm.

The adhesive layer may include a cured product of the thermosetting adhesive composition. Specifically, the adhesive layer may include a semi-cured product or a completely cured product of the thermosetting adhesive composition.

When the laminated film is a coverlay film, the adhesive layer may include a semi-finished product of the thermosetting adhesive composition. However, the present invention is not limited thereto, and the laminated film may be a synthetic resin film including an adhesive layer including a fully cured product of the thermosetting adhesive composition.

In the present specification, “semi-cured product” refers to a cured product having a degree of curing less than the maximum curing degree (ie, 100% curing degree), and “completely cured product” refers to the maximum curing degree (ie, 100% curing degree) It means a cured product having.

In addition, in the present specification, “maximum curing degree” means a degree of curing at a level at which further curing does not occur even when additional heat is applied.

The laminated film may be a coverlay film.

1 is a schematic cross-sectional view of a laminated film 100 according to an embodiment of the present invention.

The laminated film 100 of FIG. 1 may be referred to as a coverlay film.

The laminated film 100 of FIG. 1 includes a base film 111, an adhesive layer 112 and a release film 120.

The base film 111 and the adhesive layer 112 stacked thereon may be referred to as a coverlay 110.

The laminated film 100 of FIG. 1 may be manufactured by the following method. That is, after applying the thermosetting adhesive composition to the base film 111 on which the thermosetting adhesive composition is continuously running, the base film 111 on which the thermosetting adhesive composition is applied is passed through an in-line dryer, and an organic solvent is applied at 100 to 170°C for 2 to 10 minutes. It is dried by removing to form the adhesive layer 112 in a semi-cured state, and the adhesive layer 112 is compressed and laminated with the release film 120 using a roll laminator to prepare the laminated film 100. Thereafter, the degree of curing of the adhesive layer 112 may be adjusted through aging for 12 to 48 hours in a 40 to 60° C. convection oven. Methods of applying the thermosetting adhesive composition to the base film 111 include comma coating, lip coating, roll coating, gravure coating, blade coating, wire bar bar) coating, reverse coating, etc. can be used.

The release film 120 may be a release paper.

Hereinafter, a printed wiring board according to an embodiment of the present invention will be described in detail.

2 is a schematic cross-sectional view of a printed wiring board 300 according to an embodiment of the present invention.

The printed wiring board 300 of FIG. 2 includes a base film 311, an adhesive layer 312, and a metal foil laminate 320.

The metal foil laminate 320 may include a metal foil 320a etched with a circuit pattern.

As the metal foil 320a, copper, aluminum, iron, gold, silver, nickel, palladium, chromium, molybdenum, or a foil of these alloys is suitably used, and copper foil is preferable from the viewpoints of workability, flexibility, electrical conductivity, and the like.

The base film 311 and the adhesive layer 312 stacked thereon may be referred to as a coverlay 310.

The printed wiring board 300 of FIG. 2 may have a migration resistance that does not cause a short circuit within 1,000 hr when a voltage of 100V is applied under 85% relative humidity and 85°C temperature conditions.

The printed wiring board 300 may be a flexible printed circuit board.

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

Example

Examples 1 to 5 and Comparative Examples 1 to 4

(Preparation of thermosetting adhesive composition)

Modified polyimide resin (A) (manufactured by Arakawa Chemical Industries, Ltd., brand name PIAD series), long-chain alkyl bismaleimide resin (B) (manufactured by Designer Molecules Inc., brand name “BMI-3000”), epoxy resin (C) (Triglycidyl-P-aminophenol, Kukdo Chemical, brand name "PA-805"), curing accelerator (D) (2-methylimidazole) and reaction initiator (E) (2,5-dimethyl-2,5 -Di(t-butylperoxy)hexane) was mixed in toluene in the ratio shown in Table 1 to prepare a thermosetting adhesive composition having a nonvolatile content of 35% by weight. At this time, the modified polyimide resin was a mixture of PIAD100H, PIAD100L and PIAD200 in a weight ratio of 2:1:2 while stirring at room temperature (25°C). In addition, the content of toluene in the prepared thermosetting adhesive composition was 65% by weight. In Table 1 below, the units of each numerical value are parts by weight.

ingredient Example Comparative example One 2 3 4 5 One 2 3 4 A 100 100 100 100 100 100 100 100 100 B 5 15 20 15 15 3 22 15 15 C 5 5 5 3 10 5 5 2 15 D One One One One One One One One One E One One One One One One One One One

(Manufacture of coverlay film)

Each thermosetting adhesive composition prepared in Examples 1 to 5 and Comparative Examples 1 to 4 was coated on an electrically insulating substrate (thickness: 12.5 μm) and dried at 150° C. for 2 minutes to form an adhesive layer having a thickness of 20 μm. Then, a release paper (Yulchon Chemical Co., Ltd. product name: YC-7, thickness: 125 μm) was laminated on the adhesive layer to prepare a coverlay film.

(Manufacture of adhesive sheet)

Each of the thermosetting adhesive compositions prepared in Examples 1 to 5 and Comparative Examples 1 to 4 was coated on a PET release film (TAK, product name: RPK201, thickness: 38 μm) and dried at 150° C. for 2 minutes. After forming an adhesive layer having a thickness of 20 μm, a release paper (Yulchon Chemical Co., Ltd., product name: YC-7, thickness: 125 μm) was laminated on the adhesive layer to prepare an adhesive sheet.

Evaluation example

Evaluation Example 1: Evaluation of dielectric constant and dielectric loss factor

Each of the adhesive sheets prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were cured at 150° C. for 1 hour to obtain a cured sheet having a total thickness of 500 μm. Thereafter, the dielectric constant and dielectric loss tangent at 1 GHz were measured three times in accordance with ASTM D150 using a dielectric constant measuring device (RF impedance analyzer, Agilent, model name: E4991A) for each of the cured sheets, and the average value In Table 2, they are expressed as dielectric constant and dielectric loss factor.

Evaluation Example 2: Evaluation of migration resistance properties

Using each of the coverlay films prepared in Examples 1 to 5 and Comparative Examples 1 to 4, a test piece for evaluating a single layer plate having the same cross-sectional structure as the printed wiring board 300 of FIG. 3 was prepared. Specifically, a circuit pattern having a line width vs. space width of 50 µm: 50 µm was formed on the flexible copper clad laminate, and each of the coverlay films was pressed on the circuit pattern formation surface using a press device, at a temperature of 160° C. and a pressure of 45 Kgf/ A test piece for evaluation of a single-layer plate was prepared by bonding under the conditions of cm ^{2 and a pressing time of 60 minutes.} Thereafter, the migration resistance was measured by applying a DC voltage of 100V to the anode of the circuit under conditions of a temperature of 85°C and a relative humidity of 85% for each of the single-layer plate evaluation specimens, and a short circuit occurred between conductors after 1,000 hours, or When dentrite occurs, it is indicated by X in Table 2 below, and when it is not, indicated by ○.

Evaluation Example 3: Evaluation of adhesive strength

The adhesive strength of each of the coverlay films prepared in Examples 1 to 5 and Comparative Examples 1 to 4 was measured by the following method. That is, after removing the release paper of each of the coverlay films, the adhesive side of each of the coverlay films is 1oz (thickness: about 35um) rolled copper foil (manufactured by Nikko Metal Co., Ltd., electrolytic foil). ) Was pressed on the glossy surface of 160°C for 7.7 MPa for 60 minutes to prepare a coverlay adhesive copper foil. Thereafter, the electrically insulating substrate was removed, and a 2 mm wide cut was put on the coverlay adhesive copper foil prepared in this way by using a cutter. The peel strength when peeling this cut from the copper foil in the 90 degree direction under the condition of a tensile speed of 50 mm/min was measured, and the results are shown in Table 2 below.

Evaluation Example 4: Evaluation of soldering heat resistance

A sample was prepared in the same manner as the sample preparation for the evaluation of the adhesive strength of Evaluation Example 3, and each of the specimens was cut to be 50 mm in width and 50 mm in length, and treated for 24 hours in an atmosphere at a temperature of 23°C and a relative humidity of 55%. , Quickly float the coverlay film on a soldering bath at a temperature of 280° C. for 1 minute so that the coverlay film contacts the liquid material, and when peeling occurs inside the adhesive layer, it is indicated by X in Table 2, and otherwise indicated by ○.

ingredient Example Comparative example One 2 3 4 5 One 2 3 4 adhesion
Strength (N/cm) 11 8 7 9 13 12 6 5 14 Soldering heat resistance (℃) ○ ○ ○ ○ ○ ○ X X ○ permittivity 2.4 2.4 2.5 2.4 2.5 2.6 2.3 2.4 2.4 Dielectric loss factor 0.005 0.004 0.003 0.003 0.005 0.006 0.003 0.003 0.007 Resistance to migration ○ ○ ○ ○ ○ ○ ○ X ○

Referring to Table 2, when each thermosetting adhesive composition prepared in Examples 1 to 5 is used, both soldering heat resistance and migration resistance are excellent, and the adhesive strength, dielectric constant, and dielectric loss factor are also specified in each specified specification (adhesion Strength: 7N/m or more, dielectric constant: 2.5 or less, dielectric loss factor: 0.005 or less) were all satisfied. On the other hand, when each thermosetting adhesive composition prepared in Comparative Examples 1 to 4 is used, at least one of soldering heat resistance and migration resistance is poor, and/or at least one of adhesive strength, dielectric constant and dielectric loss factor is each It was found that it did not meet the specified specifications (adhesive strength: 7N/m or more, dielectric constant: 2.5 or less, dielectric loss factor: 0.005 or less).

The present invention has been described with reference to the drawings and embodiments, but these are merely exemplary, and those of ordinary skill in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: laminated film 111, 311: base film
112, 312: adhesive layer 110, 310: coverlay
120: release film 300: printed wiring board
320: metal foil laminate 320a: metal foil

Claims (15)

100 parts by weight of a modified polyimide resin which is a reactant of a monomer group containing an aromatic tetracarboxylic anhydride and a diamine;
5 to 20 parts by weight of a long-chain alkylbismaleimide resin having a main chain including an alkylene chain having 10 or more carbon atoms and a side chain including an alkyl group bonded to the alkylene chain;
3 to 10 parts by weight of an epoxy resin;
2 parts by weight or less of a reaction initiator; And
A thermosetting adhesive composition comprising 2 parts by weight or less of a curing accelerator. The method of claim 1,
The aromatic tetracarboxylic anhydride is a thermosetting adhesive composition represented by the following formula (1):
[Formula 1]

In the formula, X is a single bond, -SO ₂ -, -CO-, -O-, -OC ₆ H ₄ -C(CH ₃ ) ₂ -C ₆ H ₄ -O- or -COO-X ¹ -OCO- (X ¹ represents -(CH ₂ ) ₁ -(l=1 to 20) or -H ₂ C-HC(-OC(=O)-CH ₃ )-CH ₂ -). The method of claim 1,
The diamine is a dimer acid that is a dimer of an unsaturated fatty acid, a trimer acid that is a trimer of an unsaturated fatty acid, or all carboxyl groups in a mixture thereof with a primary amino group. The method of claim 1,
The modified polyimide resin is a thermosetting adhesive composition comprising polydimethylsiloxane. The method of claim 1,
The long-chain alkyl bismaleimide resin is a thermosetting adhesive composition comprising a compound having a maleimide group, a divalent group having at least two imide bonds, and a saturated or unsaturated divalent hydrocarbon group. The method of claim 1,
The epoxy resin is a thermosetting adhesive composition comprising a multifunctional epoxy resin having three or more epoxy groups. delete delete The method of claim 1,
The monomer group is a thermosetting adhesive composition further comprising diaminopolysiloxane. The method of claim 1,
A thermosetting adhesive composition further comprising an organic solvent, wherein the content of the organic solvent is 40 to 90 parts by weight based on 100 parts by weight of the total weight of the thermosetting adhesive composition including the organic solvent. Base film; And
Including an adhesive layer disposed on the base film,
The adhesive layer is a laminated film comprising a semi-finished product of the thermosetting adhesive composition according to any one of claims 1 to 6, 9 and 10. The method of claim 11,
The laminated film is a laminated film that is a coverlay film. A printed wiring board comprising the laminated film according to claim 11. The method of claim 13,
The printed wiring board has migration resistance characteristics in which a circuit short circuit does not occur within 1,000 hours when a voltage of 100V is applied under 85% relative humidity and 85°C temperature conditions. The method of claim 13,
The printed wiring board is a printed wiring board which is a flexible printed circuit board.

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