JP6831356B2 - Halogen-free resin composition and adhesive film, cover film, copper-clad plate produced by it - Google Patents

Description

The present invention relates to a flexible printed circuit board, and more particularly to a halogen-free resin composition and an adhesive film, a cover film, and a copper-clad board manufactured by the same.

Adhesive films, cover films and copper-clad plates are the basic materials for manufacturing flexible printed circuit boards. With the development of electronic information technology, the market demand for its performance, especially heat resistance, anti-aging property, flame retardancy and adhesiveness, is increasing. Adhesives used for commonly used adhesive films, cover films, and flexible copper-clad plates by the three-layer method are mainly composed of epoxy resin / nitrile rubber and contain a curing agent, flame retardant, and other auxiliary components. Yes, its peeling strength is generally low, and its heat resistance and anti-aging property are also inferior. In order to improve heat resistance, the Chinese patent application CN101327373B and the Chinese patent application publication CN102199413A were modified with an epoxy resin / nitrile rubber system with a bismaleimide prepolymer, and the Chinese patent application publication CN104531030A did not use nitrile rubber. It is described that the flexible epoxy system is modified with a phenol resin, and that the polyfunctional epoxy resin is cured with a flexible curing agent in the Chinese patent CN103834343B. All of the above methods can improve the heat resistance of the copper-clad plate product, but may cause a large loss in the flexible performance of the product.

Cover films and copper-clad plates manufactured by using polyurethane resin as the main resin and blending other resins such as epoxy resin and phenol resin and flame retardants, such as Japanese patent JP2009-96940A and Chinese patent application publication CN105482442A. , The flexibility and peel strength of the product are suitable. In the Chinese patent CN102822304B, an adhesive produced by blending polyurethane as a main resin with polyester resin and epoxy resin has good moisture and heat resistance, bending performance at low temperature, and fluidity. However, due to the influence of the urethane structure, polyurethane is inferior in heat resistance and anti-aging property, and has low peel strength after tin immersion.

Therefore, by using a novel resin composition, such as an adhesive film, a cover film, and a copper-clad plate manufactured from the resin composition, excellent flexibility, heat resistance, anti-aging property, and peel strength can be obtained. There is an urgent need to develop a resin composition.

With the technical problems described above as a starting point, one object of the present invention is a halogen-free resin composition containing a carboxyl group-containing polyester resin, a polyfunctional epoxy resin, and a nitrogen-containing epoxy compound as main components, and the production thereof. It is an object of the present invention to provide an adhesive film, a cover film and a copper-clad plate. The present inventors have conducted diligent studies and have reached the following inventions.

According to one aspect of the present invention, a halogen-free resin composition is provided. The halogen-free resin composition
60 to 100 parts by weight of carboxyl group-containing polyester resin;
5 to 30 parts by weight of polyfunctional epoxy resin;
0.5 to 10 parts by weight of nitrogen-containing epoxy compound;
Contains 10-40 parts by weight of flame retardant; and 40-100 parts by weight of solvent.

According to a preferred embodiment of the present invention, the carboxyl group-containing polyester resin has a number average molecular weight in the range of 5000 to 50,000, a glass transition temperature in the range of −10 ° C. to 70 ° C., and an acid value. Is in the range of 5 mgKOH / g to 50 mgKOH / g.

According to a preferred embodiment of the present invention, the epoxy equivalent of the polyfunctional epoxy resin is in the range of 100 g / equivalent to 500 g / equivalent, and the number average molecular weight is 8000 or less.

According to a preferred embodiment of the present invention, the polyfunctional epoxy resin is a phenol-type novolac epoxy resin, an orthocresol-type novolac epoxy resin, a bisphenol A-type novolac epoxy resin, a dicyclopentadiene-type epoxy resin, a biphenyl-type epoxy resin, and the like. It is at least one selected from the group consisting of naphthalene type epoxy resin and tetra functional epoxy resin.

According to a preferred embodiment of the present invention, the content of the polyfunctional epoxy resin is in the range of 10 to 30 parts by weight.

According to a preferred embodiment of the present invention, the nitrogen-containing epoxy compound has a glycidylamine structure.

According to a preferred embodiment of the present invention, the epoxy equivalent of the nitrogen-containing epoxy compound is in the range of 50 g / equivalent to 500 g / equivalent, and the number average molecular weight is 4000 or less.

According to a preferred embodiment of the present invention, the nitrogen-containing epoxy compound is tetraglycidyldiaminodiphenylmethane, triglycidyl p-aminophenol, tetraglycidylbisaminomethylcyclohexanone and N, N, N', N'-tetraglycidyl m. -At least one selected from the group consisting of xylene diamines.

According to a preferred embodiment of the present invention, the content of the nitrogen-containing epoxy compound is in the range of 1 to 5 parts by weight.

According to a preferred embodiment of the present invention, the flame retardant is a phosphorus-containing flame retardant or a nitrogen-containing flame retardant.

According to a preferred embodiment of the present invention, the halogen-free resin composition further comprises 0 to 2 parts by weight of a curing accelerator.

According to a preferred embodiment of the present invention, the curing accelerator is at least selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, undecylimidazole and cyanoimidazole. There is one type.

According to a preferred embodiment of the present invention, the halogen-free resin composition further comprises 0 to 2 parts by weight of an amine-based curing agent.

According to a preferred embodiment of the present invention, the amine-based curing agent is at least one selected from the group consisting of dicyandiamide, 4,4'-diaminodiphenyl sulfone and 4,4'-diaminodiphenyl ether.

According to a preferred embodiment of the present invention, the halogen-free resin composition further comprises 0 to 2 parts by weight of blocked isocyanate.

According to a preferred embodiment of the present invention, the blocked isocyanate is at least one selected from the group consisting of blocked tolylene diisocyanate, blocked hexamethylene diisocyanate and blocked isophorone diisocyanate.

According to a preferred embodiment of the present invention, the solvent is one selected from the group consisting of acetone, butanone, cyclohexanone, toluene, ethylene glycol methyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate and dimethylformamide. There are two or more types.

According to another aspect of the present invention, an adhesive film is provided. The above adhesive film is
Release film and
An adhesive layer made of the halogen-free resin composition laminated on the release film and
Includes paper pattern.

According to a preferred embodiment of the present invention, the thickness of the release film is in the range of 50 μm to 150 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the release paper is 50 μm. It is in the range of to 150 μm.

According to another aspect of the present invention, a cover film is provided. The above cover film
Polyimide layer and
An adhesive layer made of the halogen-free resin composition laminated on the polyimide layer and
Includes a paper pattern laminated on the adhesive layer.

According to a preferred embodiment of the present invention, the thickness of the polyimide layer is in the range of 10 μm to 100 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the release paper is 50 μm or more. It is within the range of 150 μm.

According to yet another aspect of the present invention, a copper-clad plate is provided. The copper-clad plate is
Polyimide layer and
An adhesive layer made of the halogen-free resin composition laminated on the polyimide layer and
Includes a copper foil laminated on the adhesive layer.

According to a preferred embodiment of the present invention, the thickness of the polyimide layer is in the range of 10 μm to 100 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the copper foil is in the range of 6 μm or more. It is within the range of 70 μm.

The advantages of the present invention as compared with the prior art in the art are as follows. The carboxyl group-containing polyester resin in the halogen-free resin composition of the present invention can react with the polyfunctional epoxy resin and the nitrogen-containing epoxy compound, and the nitrogen-containing epoxy compound is self-polymerization of the polyfunctional epoxy resin and the carboxyl group-containing polyester resin. Since the reaction with the resin can be promoted, the adhesive can form a mutual penetration network structure, and the cured product has excellent heat resistance, binding performance and ion transfer resistance. The adhesive film, cover film and copper-clad plate produced from the halogen-free resin composition have excellent heat resistance, anti-aging property, flexible performance and high peel strength. Copper-clad plate products, and adhesive films and cover films bonded to copper foil can pass the high-temperature tin immersion test at 360 ° C. for 20 seconds. The peel strength retention rate after 60 seconds of tin immersion at 288 ° C. is high, the peel strength retention rate after high temperature aging treatment is high, and the flame retardancy grade reaches UL94-V0.

Of course, it should be understood that one of ordinary skill in the art can devise and make changes to various other embodiments in accordance with the teachings of this specification without departing from the scope or gist of the present disclosure. is there. Therefore, the following specific embodiments are not limited.

Unless otherwise noted, all numbers representing the dimensions, quantities, and physical and chemical features of features used herein and in the claims are modified by the term "about" in all cases. It should be understood as a thing. Therefore, unless otherwise stated, the numerical parameters described above and in the claims are approximate values, and those skilled in the art will use the teachings disclosed herein to obtain the desired properties. These approximate values can be changed appropriately in order to obtain. When using the numerical range represented by the endpoints, all numerical values within the range and any range within the range are included, for example, 1 to 5 are 1, 1.1, 1.3. , 1.5, 2, 2.75, 3, 3.80, 4 and 5 and the like.

According to one aspect of the present invention, a halogen-free resin composition is provided. The halogen-free resin composition
60 to 100 parts by weight of carboxyl group-containing polyester resin;
5 to 30 parts by weight of polyfunctional epoxy resin;
0.5 to 10 parts by weight of nitrogen-containing epoxy compound;
Contains 10-40 parts by weight of flame retardant; and 40-100 parts by weight of solvent.

According to the above-mentioned technical proposal of the present invention, the above-mentioned halogen-free resin composition of the present invention uses a carboxyl group-containing polyester resin as a main resin, which can be dissolved together with a polyfunctional epoxy resin in a cyclic solvent and can react with each other. And can form a cross-penetrating network structure with the polyfunctional epoxy resin; the nitrogen-containing epoxy compound can promote the self-polymerization of the polyfunctional epoxy resin and the cross-linking between it and the carboxyl group-containing polyester resin, and more and more types. Since many cross-linking points can be formed, the performance of the cured product is improved. For example, the adhesive film, cover film and copper-clad plate produced by the halogen-free resin composition of the present invention have advantages such as halogen-free, high temperature resistance, anti-aging, excellent flexibility and high peel strength.

Specifically, the number average molecular weight of the carboxyl group-containing polyester resin is in the range of 5,000 to 50,000, the glass transition temperature is in the range of -10 ° C to 70 ° C, and the acid value is 5 mgKOH / g to 50 mgKOH /. It is within the range of g. When the acid value of the carboxyl group-containing polyester resin is less than 5 mgKOH / g, the crosslink density of the halogen-free resin composition after curing becomes low, and the mechanical properties deteriorate. When the acid value of the carboxyl group-containing polyester resin exceeds 50 mgKOH / g, the flexibility of the halogen-free resin composition after it is completely cured becomes low, and the filling property for wiring becomes poor. The content of the carboxyl group-containing polyester resin is 60 to 100 parts by weight, preferably 70 to 100 parts by weight. If the amount used is too large, the crosslink density of the resin composition decreases and the heat resistance decreases; if the amount used too small, the flexibility of the resin composition decreases, and the cover film produced thereby reduces the flexibility. The glue squeezes out a lot and the usability deteriorates. As a specific example of the above-mentioned carboxyl group-containing polyester resin that can be used in the present invention, BX-39SS from Nippon Toyo Spinning Co., Ltd. (its number average molecular weight is 16000, glass transition temperature is 15 ° C., acid value is 17 mgKOH / g, and solid content is contained. The amount is 40% by weight).

Specifically, the epoxy equivalent of the polyfunctional epoxy resin used in the present invention is in the range of 100 g / equivalent to 500 g / equivalent, and the number average molecular weight is 8000 or less. Preferably, the polyfunctional epoxy resin has a number average molecular weight of 6000 or less. Preferably, the polyfunctional epoxy resin has a number average molecular weight of 400 or more. Preferably, the polyfunctional epoxy resin is a phenol type novolac epoxy resin, an orthocresol type novolak epoxy resin, a bisphenol A type novolak epoxy resin, a dicyclopentadiene type epoxy resin, a biphenyl type epoxy resin, a naphthalene type epoxy resin and a tetrafunctional epoxy resin. At least one selected from the group consisting of resins. The polyfunctional epoxy resin can improve the curing crosslink density of the resin composition, and can further improve the heat resistance and anti-aging property of the adhesive film, cover film and copper-clad plate made of the resin composition. .. Preferably, the polyfunctional epoxy resin is an orthocresol type novolak epoxy resin having a molecular weight of 6000 or less. Preferably, the content of the polyfunctional epoxy resin is in the range of 10 to 30 parts by weight. If the amount of the polyfunctional epoxy resin used is too small, the crosslink density of the adhesive film, the cover film and the copper-clad plate made of the resin composition becomes low. If the amount of the polyfunctional epoxy resin used is too large, the flexibility of the adhesive film, the cover film, and the copper-clad plate made of the resin composition deteriorates. Preferably, the content of the polyfunctional epoxy resin is in the range of 10 to 20 parts by weight. As a specific example of the polyfunctional epoxy resin used in the present invention, the orthocresol type novolac epoxy resin KEC-2185A75 (its epoxy equivalent is 214 g / eq, number average molecular weight is 1100, and solid content is 75 weight) from Koron Korea. %).

According to the technical proposal of the present invention, a nitrogen-containing epoxy compound is added to the halogen-free resin composition. The nitrogen-containing epoxy compound can promote the reaction between the polyfunctional epoxy resin and the carboxyl group-containing polyester resin and the self-polymerization reaction of the polyfunctional epoxy resin, and by heating at a relatively low temperature for a short time, this The resin composition of the present invention can be semi-cured. Preferably, the nitrogen-containing epoxy compound has a glycidylamine structure. Preferably, the epoxy equivalent of the nitrogen-containing epoxy compound is in the range of 80 g / equivalent to 300 g / equivalent, and the number average molecular weight is in the range of 2000 or less. At least the nitrogen-containing epoxy compound is selected from the group consisting of tetraglycidyl diaminodiphenylmethane, triglycidyl p-aminophenol, tetraglycidyl bisaminomethylcyclohexanone and N, N, N', N'-tetraglycidyl m-xylene diamine. There is one type. Most preferably, the nitrogen-containing epoxy compound is triglycidyl p-aminophenol. The content of the nitrogen-containing epoxy compound is 0.5 to 10 parts by weight. When the amount of the nitrogen-containing epoxy compound is less than 0.5 parts by weight, the accelerating effect is deteriorated, and it takes time to bring it into a semi-cured state. When the amount of the nitrogen-containing epoxy compound exceeds 10 parts by weight, the rigidity is too high, the binding property is lowered, the cross-linking reaction is easily promoted during storage, and the storability of the adhesive liquid is deteriorated. Preferably, the content of the nitrogen-containing epoxy compound is 1 to 5 parts by weight. Specific examples of the nitrogen-containing epoxy compound include triglycidyl p-aminophenol AFG-90 from Shanghai Huayi (the epoxy equivalent is 105 g / equivalent and the number average molecular weight is 277). Preferably, the content of the nitrogen-containing epoxy compound is in the range of 1 to 5 parts by weight.

According to the technical proposal of the present invention, a flame retardant is added to the halogen-free resin composition in order to impart a halogen-free flame retardancy to the cured resin composition. When used in the production of cover films, the amount of flame retardant added affects not only flame retardancy but also the amount of protrusion, peel strength, and storage period. There is no limitation on the specific type of the flame retardant used in the present invention, the flame retardant effect can be provided, the interaction of each component in the halogen-free resin composition is not affected, and the halogen-free resin is used. Anything that does not affect the mechanical properties of the cover film made of the composition may be used. Preferably, the flame retardant is a phosphorus-containing flame retardant or a nitrogen-containing flame retardant. Specific examples of the phosphorus-containing flame retardant include OP-930 and OP-935 manufactured by Clariant AG of Germany, and SPB-100 manufactured by Otsuka Chemical Co., Ltd. of Japan. Among the phosphorus-containing flame retardants, OP-935 having a high flame retardant efficiency and a small particle size is preferably used. Specific examples of the nitrogen-containing flame retardant include MC-5S manufactured by Mitsubishi Japan Gas Co., Ltd. and HT-209 manufactured by Taixing Chemical Company. As the nitrogen-containing flame retardant, MC-5S having good dispersibility is preferably used. According to the technical proposal of the present invention, the halogen-free resin composition contains 10 to 40 parts by weight of a flame retardant.

In order to further improve the crosslink density of the obtained adhesive, the halogen-free resin composition may optionally contain one or more of a curing accelerator, an amine-based curing agent and a blocked isocyanate. Preferably, the curing accelerator is at least one selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, undecylimidazole and cyanoimidazole. Further, the halogen-free resin composition contains 0 to 2 parts by weight of a curing accelerator. Preferably, the amine-based curing agent is at least one selected from the group consisting of dicyandiamide, 4,4'-diaminodiphenyl sulfone and 4,4'-diaminodiphenyl ether. In addition, the halogen-free resin composition contains 0 to 2 parts by weight of an amine-based curing agent. Preferably, the blocked isocyanate is at least one selected from the group consisting of blocked tolylene diisocyanate, blocked hexamethylene diisocyanate and blocked isophorone diisocyanate. Further, the halogen-free resin composition contains 0 to 2 parts by weight of blocked isocyanate.

A solvent is added to the halogen-free resin composition of the present invention so as to dissolve each component. Further, in order to adjust the viscosity of the produced resin adhesive liquid, the solid content of the resin composition is adjusted. The specific type of solvent used in the present invention is not limited as long as it can dissolve or disperse each component and does not affect the effect of the present invention. Preferably, the solvent is one or more selected from acetone, butanone, cyclohexanone, toluene, ethylene glycol methyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate and dimethylformamide.

According to another aspect of the present invention, an adhesive film is provided. The above adhesive film
Release film and
An adhesive layer made of the halogen-free resin composition laminated on the release film and
Includes paper pattern.

Preferably, the thickness of the release film is in the range of 50 μm to 150 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the release paper is in the range of 50 μm to 150 μm.

In the method for producing the adhesive film, the halogen-free resin composition is applied to the release surface of the release film, and the release film coated with the halogen-free resin composition is applied at a high temperature of 120 to 160 ° C. It includes a step of placing it in a test device, baking it for 2 to 6 minutes to perform semi-curing, and further adhering the release paper to the semi-cured adhesive layer.

According to another aspect of the present invention, a cover film is provided. The above cover film
Polyimide layer and
An adhesive layer made of the halogen-free resin composition laminated on the polyimide layer and
Includes a paper pattern laminated on the adhesive layer.

Preferably, the thickness of the polyimide layer is in the range of 10 μm to 100 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the release paper is in the range of 50 μm to 150 μm.

In the method for producing the cover film, the halogen-free resin composition is applied to the surface of the polyimide thin film, and the polyimide layer coated with the coated resin composition is placed in a high-temperature test apparatus at 120 to 160 ° C. , A step of baking for 2 to 6 minutes to perform semi-curing, and further laminating the release paper to the semi-cured adhesive layer is included.

According to yet another aspect of the present invention, a copper-clad plate is provided. The copper-clad plate is
Polyimide layer and
An adhesive layer made of the halogen-free resin composition laminated on the polyimide layer and
Includes a copper foil laminated on the adhesive layer.

Preferably, the thickness of the polyimide layer is in the range of 10 μm to 100 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the copper foil is in the range of 6 μm to 70 μm.

Preferably, the copper-clad plate is a single-sided plate or a double-sided plate by a three-layer method. Taking a single-sided plate as an example, a single-sided copper-clad plate by a three-layer method is formed on a polyimide layer, an adhesive layer made of the halogen-free resin composition laminated on one side of the polyimide layer, and the adhesive layer. Includes laminated copper foil. Preferably, the thickness of the polyimide layer is in the range of 10 μm to 100 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the copper foil is in the range of 6 μm to 70 μm. The method for manufacturing a single-sided copper-clad plate by the three-layer method is as follows. That is, the halogen-free resin composition is applied to one side surface of the polyimide film, the polyimide film to which the resin composition is applied is placed in a high temperature test apparatus at 120 to 160 ° C., and baked for 2 to 6 minutes. This is a method in which a copper foil is attached to a semi-cured adhesive layer, and the composition in this semi-cured state is post-cured according to a set program.

Hereinafter, the present invention will be described in more detail with reference to Examples. It should be noted that these descriptions and examples are not intended to limit the present invention, but to facilitate the understanding of the present invention. The scope of protection of the present invention is the scope of claims.

Unless otherwise specified, the reagents used in the present invention are all commercially available products and are used as they are without further purification. Also, the mentioned "part" is a "weight part".

Measuring method In the contents disclosed in the present invention, each performance (embedding property, extreme immersion resistant soldering) of the cover film or copper-clad plate obtained in Examples 1 to 8 and Comparative Examples 1 to 8 below. Temperature, peel strength, flame retardancy and immersion soldering resistance) were measured. The specific measurement method is as follows.

Embedding property The embedding property can qualitatively reflect the filling ability of the cover films obtained in Examples 1 to 4 and Comparative Examples 1 to 4 below for a circuit in a printed circuit board. The implantability was measured by the method specifically described below.

The cover films obtained in the following examples and comparative examples were attached to the test circuit, respectively, and then quick-pressed for 80s at 180 ° C. and 100 kgf using an EWEDO-KY04C quick press machine, and with a magnifying glass of 50 times or more. Observations were made to check for lack of adhesive, foam, poor filling, unconsolidation or other defects affecting use between the circuits.

The test circuit contains 100 mm ± 10 mm long straight, semicircular and right angle patterns, the copper thickness of the circuit is 25 μm, and the line width and space width are 100 μm.

According to the measurement results, if there is no lack of adhesive, foam, poor filling, unconsolidation or other defects that affect use, it is evaluated as acceptable, otherwise it is evaluated as rejected.

Extreme immersion resistant soldering temperature The ultimate immersion resistant soldering temperature is for qualitatively reflecting the heat resistance of the cover film or copper-clad plate obtained in Examples 1 to 8 and Comparative Examples 1 to 8. Is. The ultimate immersion resistant soldering temperature was specifically measured by the method described below.

Cover film: The release paper of the cover film obtained in the following Examples and Comparative Examples is peeled off, and the adhesive layer of the cover film is bonded to the glossy surface of a copper foil having a size of 5 cm × 5 cm, and the EWEDO-KY04C quick press machine is used. After quick pressing at 180 ° C. and 100 kgf for 1 minute, the copper foil was placed in a general constant temperature test apparatus and cured at 170 ° C. for 1 hour to obtain a copper foil to which a cover film was attached. Multiple samples are produced, immersed in a tin solution at 280 + 10 n ° C. (n = 1, 2, 3, 4, 5, 6, 7 and 8) for 20 seconds, taken out, and then layer-separated, melted or foamed. Was observed to exist. The highest temperature that can be passed was set as the ultimate immersion resistant soldering temperature.

Copper-clad plate: After curing the copper-clad plates obtained in the following Examples and Comparative Examples at 170 ° C. for 2 hours, a 5 cm × 5 cm sample was cut out and tested according to the tin dipping method of the cover film.

Peeling strength The release paper is peeled off from each of the cover films obtained in Examples 1 to 4 and Comparative Examples 1 to 4 below, and the adhesive layer of the cover film is 20 cm (long) in size × It is bonded to the glossy surface of a copper foil of 20 cm (width) x 18 μm (thickness), and quickly pressed for 1 minute at 180 ° C. and 100 kgf using an EWEDO-KY04C quick press machine, and then put into a general constant temperature test device. After standing at 170 ° C. for 1 hour, copper foils to which cover films corresponding to Examples 1 to 4 and Comparative Examples 1 to 4 were attached were obtained.

According to the IPC-TM-6502.4.9 method, the copper foil to which the cover films corresponding to Examples 1 to 4 and Comparative Examples 1 to 4 obtained by the above method are attached, and the following Examples 5 to 4 are attached. The peel strength of the copper-clad plates obtained in No. 8 and Comparative Examples 5 to 8 was measured. The measurement results are shown in Tables 1 to 4 below. Among them, the "peeling strength (A state)" is the peeling strength measured without any treatment on the copper foil or the copper-clad plate to which the manufactured cover film is attached; "Peeling strength (288 ° C. tin immersion 20s)" ) ”Is the peel strength measured after immersing the manufactured cover film or copper clad plate in a tin solution at 288 ° C for 20 seconds;“ peel strength (288 ° C tin dipping 60s) ”is manufactured. The peel strength measured after immersing the cover film or copper-clad plate in a tin solution at 288 ° C. for 60 seconds; “peeling strength (170 ° C. aging 10h)” means the manufactured cover film or copper-clad plate. It is the peeling strength measured after aging at 170 ° C. for 10 hours.

Flame Retardant The flame retardancy of the cover film or copper-clad plate obtained in Examples 1 to 8 and Comparative Examples 1 to 8 below was measured according to the UL94 vertical combustion method. Among them, the cover films obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were laminated with GOULD 18 μm rolled copper foil, cured, and then measured.

Example 1
90 parts by weight of carboxyl group-containing polyester resin (BX-39SS from Japan Toyo Spinning Co., Ltd.), 8 parts by weight of orthocresol type epoxy resin (KEC-2185A75 from Koron Korea), 2 parts by weight of triglycidyl p-amino A phenol (AFG-90 from Shanghai Huayi), 25 parts by weight of nitrogen-containing flame retardant (MC-5S from Mitsubishi Japan Gas Co., Ltd.) and 50 parts by weight of butanone (MEK) solvent are mixed, stirred and halogen. A free resin composition (resin adhesive liquid) was obtained.

The resin adhesive liquid is applied to a polyimide thin film (Taimide TL-012, Taiwan Taimide) having a thickness of 12.5 μm with an applicator so that the thickness of the adhesive coating (dry adhesive) is 15 μm, and then 140 ° C. The adhesive layer was partially crosslinked and cured on the polyimide thin film by baking for 2 minutes in the high temperature test apparatus of. Then, a release paper (thickness 50 μm, Sumitomo Chemical Japan Co., Ltd.) was laminated with the adhesive layer to manufacture a cover film for a flexible printed circuit board.

Example 2
70 parts by weight of carboxyl group-containing polyester resin (BX-39SS from Japan Toyo Spinning Co., Ltd.), 25 parts by weight of orthocresol type epoxy resin (KEC-2185A75 from Koron Korea), 5 parts by weight of triglycidyl p-amino Phenol (AFG-90 from Shanghai Huayi), 25 parts by weight of nitrogen-containing flame retardant (MC-5S from Mitsubishi Japan Gas Co., Ltd.) and 75 parts by weight of butanone (MEK) solvent are mixed, stirred and halogen. A free resin composition (resin adhesive liquid) was obtained.

A cover film for a flexible printed circuit board was manufactured by a method similar to that of Example 1.

Example 3
80 parts by weight of carboxyl group-containing polyester resin (BX-39SS from Japan Toyo Spinning Co., Ltd.), 17 parts by weight of orthocresol type epoxy resin (KEC-2185A75 from Koron Korea), 3 parts by weight of triglycidyl p-amino Phenol (AFG-90 from Shanghai Huayi), 15 parts by weight of nitrogen-containing flame retardant (MC-5S from Mitsubishi Japan Gas Co., Ltd.) and 45 parts by weight of butanone (MEK) solvent are mixed, stirred and halogen. A free resin composition (resin adhesive liquid) was obtained.

A cover film for a flexible printed circuit board was manufactured by a method similar to that of Example 1.

Example 4
80 parts by weight of carboxyl group-containing polyester resin (BX-39SS from Japan Toyo Spinning Co., Ltd.), 17 parts by weight of orthocresol type epoxy resin (KEC-2185A75 from Koron Korea), 3 parts by weight of triglycidyl p-amino Phenol (AFG-90 from Shanghai Huayi), 15 parts by weight of nitrogen-containing flame retardant (OP-935 from Clariant, Germany) and 45 parts by weight of butanone (MEK) solvent are mixed, stirred and halogen-free. A resin composition (resin adhesive liquid) was obtained.

A cover film for a flexible printed circuit board was manufactured by a method similar to that of Example 1.

Example 5
The halogen-free resin composition obtained in Example 1 was applied to a 12.5 μm polyimide thin film (Taimide TL-012, Taiwan Taimide) so that the thickness of the adhesive (dry adhesive) was 15 μm. The polyimide thin film coated with the halogen-free resin composition was placed in a high-temperature test apparatus at 140 ° C. and baked for 2 minutes to be semi-cured. Further, a rolled copper foil (BHY-22B-T from Nippon Mining) having a size of 40 cm (length) x 25 cm (width) x 18 μm (thickness) is laminated on a semi-cured adhesive layer and laminated at 100 ° C. , 60 s quick press at a pressure of 180 ° C./100 kg and cured at 170 ° C. for 2 hours to produce a single-sided copper-clad plate for a flexible printed circuit board.

Example 6
A single-sided copper-clad plate for a flexible printed circuit board was manufactured by the same method as in Example 5 except that the halogen-free resin composition obtained in Example 2 was used.

Example 7
A single-sided copper-clad plate for a flexible printed circuit board was manufactured by the same method as in Example 5 except that the halogen-free resin composition obtained in Example 3 was used.

Example 8
A single-sided copper-clad plate for a flexible printed circuit board was manufactured by the same method as in Example 5 except that the halogen-free resin composition obtained in Example 4 was used.

Comparative Example 1
75 parts by weight polyester type polyurethane resin (UR-3500 from Japan Toyo Spinning Company, its acid value is 35 mgKOH / g), 20 parts by weight orthocresol type epoxy resin (KEC-2185A75 from Korea Koron), 5 weight A mixture of 25 parts by weight of triglycidyl p-aminophenol (AFG-90 from Shanghai Huayi), 25 parts by weight of a nitrogen-containing flame retardant (MC-5S from Mitsubishi Japan Gas Co., Ltd.) and 70 parts by weight of butanone (MEK) solvent. Then, the mixture was stirred to obtain a halogen-free resin composition (resin adhesive solution).

A cover film for a flexible printed circuit board was manufactured by a method similar to that of Example 1.

Comparative Example 2
75 parts by weight of carboxyl group-containing polyester resin (BX-39SS from Japan Toyo Spinning Co., Ltd.), 20 parts by weight of orthocresol type epoxy resin (KEC-2185A75 from Koron Korea), 5 parts by weight of blocked isocyanate (Degussa, Germany) B-1358A), 25 parts by weight of nitrogen-containing flame retardant (MC-5S from Mitsubishi Japan Gas Co., Ltd.) and 70 parts by weight of butanone (MEK) solvent are mixed and stirred to form a halogen-free resin composition. (Resin adhesive liquid) was obtained.

A cover film for a flexible printed circuit board was manufactured by a method similar to that of Example 1.

Comparative Example 3
75 parts by weight of carboxyl group-containing polyester resin (BX-39SS from Japan Toyo Spinning Co., Ltd.), 25 parts by weight of orthocresol type epoxy resin (KEC-2185A75 from Koron Korea), 25 parts by weight of nitrogen-containing flame retardant ( MC-5S) from Mitsubishi Japan Gas Co., Ltd. and 65 parts by weight of butanone (MEK) solvent were mixed and stirred to obtain a halogen-free resin composition (resin adhesive solution).

A cover film for a flexible printed circuit board was manufactured by a method similar to that of Example 1.

Comparative Example 4
50 parts by weight of carboxyl group-containing polyester resin (BX-39SS from Japan Toyo Spinning Co., Ltd.), 35 parts by weight of orthocresol type epoxy resin (KEC-2185A75 from Koron Korea), 15 parts by weight of triglycidyl p-amino A phenol (AFG-90 from Shanghai Huayi), 25 parts by weight of nitrogen-containing flame retardant (MC-5S from Mitsubishi Japan Gas Co., Ltd.) and 100 parts by weight of butanone (MEK) solvent are mixed, stirred and halogen. A free resin composition (resin adhesive liquid) was obtained.

A cover film for a flexible printed circuit board was manufactured by a method similar to that of Example 1.

Comparative Example 5
A single-sided copper-clad plate for a flexible printed circuit board was manufactured by the same method as in Example 5 except that the halogen-free resin composition obtained in Comparative Example 1 was used.

Comparative Example 6
A single-sided copper-clad plate for a flexible printed circuit board was manufactured by the same method as in Example 5 except that the halogen-free resin composition obtained in Comparative Example 2 was used.

Comparative Example 7
A single-sided copper-clad plate for a flexible printed circuit board was manufactured by the same method as in Example 5 except that the halogen-free resin composition obtained in Comparative Example 3 was used.

Comparative Example 8
A single-sided copper-clad plate for a flexible printed circuit board was manufactured by the same method as in Example 5 except that the halogen-free resin composition obtained in Comparative Example 4 was used.

According to the measurement method described in the item of the above measurement method , each performance of the cover film or the copper-clad plate obtained in Examples 1 to 8 and Comparative Examples 1 to 8 (embeddability, extreme immersion-resistant soldering temperature, Peeling strength, flame retardancy and immersion soldering resistance) were measured. Among them, the measurement results of the cover film for the flexible printed circuit board are shown in Tables 1 and 2 below; the measurement results of the single-sided copper-clad plate for the flexible printed circuit board are shown in Tables 3 to 4 below.

As can be seen from the measurement results of Examples 1 to 4 in Table 1, the cover film produced by the halogen-free resin composition of the present invention has excellent heat resistance, and the ultimate immersion-resistant soldering temperature is 360 ° C. The retention rate of the peel strength in 20 s of tin immersion at 288 ° C. exceeded 85%. When a nitrogen-containing flame retardant is blended, the retention rate of the peel strength at 288 ° C. tin immersion 60s still exceeds 85%, the peel strength of some products is further improved, and the peel strength after 10 hours of aging at 170 ° C. The retention rate exceeded 80% in each case. In addition, the amount of protrusion of the cover film was appropriate, the embedding property was passed, and the flammability after the copper foil was laminated reached the V0 level.

On the other hand, as can be seen from the measurement results of Comparative Examples 1 to 4 in Table 2, the cover film produced by the polyurethane adhesive in Comparative Example 1 is produced from the resin composition of the present invention at an extreme immersion-resistant soldering temperature. It was clearly lower than that of the covered film, and the peel strength after tin immersion was sharply reduced. In Comparative Example 2, the resin composition was cured by isocyanate instead of the nitrogen-containing epoxy compound to obtain a cover film. Although there was no foaming phenomenon under the condition of soaking in tin at 360 ° C., the sharp decrease in peel strength after soaking in tin at 288 ° C. indicated that the overall heat resistance was poor. As can be seen from the results of Comparative Example 3, without the nitrogen-containing epoxy compound as the curing accelerator, it took a long time to reach the semi-cured state of the adhesive, and the peel strength after immersion in tin at 288 ° C. decreased sharply. .. Further, it was found that although the type of resin used in Comparative Example 4 was the same as that of the present invention, the proportions of the components were different, so that the heat resistance was poor and the embedding property was deteriorated. Therefore, for the resin composition of the present invention, it is necessary not only to combine a carboxyl group-containing polyester resin, a polyfunctional epoxy resin, and a nitrogen-containing epoxy compound, but also to require a blending ratio of each component. Only in this case can a cover film having excellent performance be manufactured.

As can be seen from Tables 3 and 4, the relationship between the peel strength of the single-sided copper-clad plate for flexible printed circuit boards, the immersion soldering resistance, the anti-aging property and the formulation of the halogen-free resin composition is as follows: cover film and halogen-free. It is similar to the relationship with the formulation of resin compositions. The copper-clad plate obtained in the examples carried out according to the above-mentioned method of the present invention has excellent performance.

As can be seen from the above, the halogen-free resin composition of the present invention contains a carboxyl group-containing polyester resin, a polyfunctional epoxy resin, a nitrogen-containing epoxy compound, a flame retardant, and a charged solvent. Among them, the carboxyl group-containing polyester resin can react with the polyfunctional epoxy resin, the polyfunctional epoxy resin can generate a self-polymerization reaction, and the nitrogen-containing epoxy compound can promote the above reaction, and can penetrate each other. Since the formation of the network structure can be promoted, the cured product has excellent heat resistance, anti-aging property and binding performance.

The cover film and the copper-clad plate produced from the resin composition of the present invention have excellent heat resistance, anti-aging property and high peel strength, and the flame retardancy level after the copper foil is laminated is UL94-V0 level. Has reached, and the overall performance is also excellent.

In the present invention, specific embodiments are presented and described, but as can be understood by those skilled in the art, substitutes for the specific embodiments presented and described without departing from the scope of the present invention. Various alternative and / or equivalent embodiments are available for. The present application is intended to include any improvement or modification to the specific embodiments discussed in the present invention. Therefore, the present invention is limited to the claims and their equivalents.

As will be appreciated by those skilled in the art, various modifications and modifications can be made without departing from the scope of the present invention. Such modifications and modifications are included within the scope of the invention, which is limited by the claims of the present application.

Claims (18)

60 to 100 parts by weight of carboxyl group-containing polyester resin;
5 to 30 parts by weight of polyfunctional epoxy resin;
1 to 10 parts by weight of nitrogen-containing epoxy compound;
Contains 10-40 parts by weight of flame retardant; and 40-100 parts by weight of solvent.
The number average molecular weight of the carboxyl group-containing polyester resin is in the range of 5000 to 50,000, the glass transition temperature is in the range of -10 ° C to 70 ° C, and the acid value is in the range of 5 mgKOH / g to 50 mgKOH / g. And
The polyfunctional epoxy resin is at least one selected from the group consisting of phenol-type novolac epoxy resin, orthocresol-type novolac epoxy resin, bisphenol A-type novolac epoxy resin, biphenyl-type epoxy resin, naphthalene-type epoxy resin, and tetra-functional epoxy resin. Kind,
The nitrogen-containing epoxy compound is triglycidyl p-aminophenol.
Halogen-free resin composition. The halogen-free resin composition according to claim 1, wherein the epoxy equivalent of the polyfunctional epoxy resin is in the range of 100 g / equivalent to 500 g / equivalent, and the number average molecular weight is 8000 or less. The halogen-free resin composition according to claim 1, wherein the content of the polyfunctional epoxy resin is in the range of 10 to 30 parts by weight. The halogen-free resin composition according to claim 1, wherein the content of the nitrogen-containing epoxy compound is in the range of 1 to 5 parts by weight. The halogen-free resin composition according to claim 1, wherein the flame retardant is a phosphorus-containing flame retardant or a nitrogen-containing flame retardant. The halogen-free resin composition according to claim 1, wherein the halogen-free resin composition further contains 0 to 2 parts by weight of a curing accelerator. 6. The method according to claim 6 , wherein the curing accelerator is at least one selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, undecylimidazole and cyanoimidazole. Halogen-free resin composition. The halogen-free resin composition according to claim 1, wherein the halogen-free resin composition further contains 0 to 2 parts by weight of an amine-based curing agent. The halogen-free resin composition according to claim 8 , wherein the amine-based curing agent is at least one selected from the group consisting of dicyandiamide, 4,4'-diaminodiphenyl sulfone and 4,4'-diaminodiphenyl ether. The halogen-free resin composition according to claim 1, wherein the halogen-free resin composition further contains 0 to 2 parts by weight of blocked isocyanate. The halogen-free resin composition according to claim 10 , wherein the blocked isocyanate is at least one selected from the group consisting of blocked tolylene diisocyanate, blocked hexamethylene diisocyanate and blocked isophorone diisocyanate. The halogen-free according to claim 1, wherein the solvent is one or more selected from acetone, butanone, cyclohexanone, toluene, ethylene glycol methyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate and dimethylformamide. Resin composition. Release film and
An adhesive layer made of the halogen-free resin composition according to any one of claims 1 to 12 laminated on the release film.
Adhesive film, including paper pattern. 13. Claim 13 that the thickness of the release film is in the range of 50 μm to 150 μm, the thickness of the adhesive layer is in the range of 5 μm to 45 μm, and the thickness of the release paper is in the range of 50 μm to 150 μm. Adhesive film described in. Polyimide layer and
An adhesive layer made of the halogen-free resin composition according to any one of claims 1 to 12 laminated on the polyimide layer.
A cover film containing a release paper laminated on the adhesive layer. In the range thickness of 10μm to 100μm of the polyimide layer is in a range thickness of 5μm to 45μm for the adhesive layer, and the thickness of the release paper is in the range of 50μm to 150 [mu] m, to claim 15 The cover film described. Polyimide layer and
An adhesive layer made of the halogen-free resin composition according to any one of claims 1 to 12 laminated on the polyimide layer.
A copper-clad plate containing a copper foil laminated on the adhesive layer. In the range thickness of 10μm to 100μm of the polyimide layer is in a range thickness of 5μm to 45μm for the adhesive layer, and the thickness of the copper foil is in the range of 6μm to 70 [mu] m, in claim 17 The copper-clad plate described.