JP2014062249A - Epoxy resin composition for insulation, insulating film, prepreg and printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition for insulation excellent in thermal, mechanical and electrical characteristics, an insulating film, a prepreg and a printed circuit board.SOLUTION: The epoxy resin composition for insulation comprises: a LiCl/DMAc cellulose aqueous solution or LiCl/DMF cellulose aqueous solution; a liquid crystal oligomer or soluble thermosetting liquid crystal oligomer; an epoxy resin; and an inorganic filler.

Description

  The present invention relates to an insulating epoxy resin composition, an insulating film, a prepreg, and a printed circuit board.

  Recently, with the development of electronic devices and demands for complex functions, printed circuit boards have been increasingly reduced in weight, thickness and size. In order to satisfy such a requirement, the wiring of the printed circuit is further complicated, and the density and functionality are increased.

  As described above, due to the downsizing and high performance of electronic devices, high density, high functionality, downsizing, thinning, and the like are also demanded in multilayer printed circuit boards. In particular, developments for finer and higher density wiring of multilayer printed circuit boards are in progress. As a result, thermal, mechanical, and electrical characteristics are important in the insulating layer of the multilayer printed circuit board.

  In particular, in order to minimize warpage that occurs when reflow is performed in the mounting process of electronic and electrical devices, a low coefficient of thermal expansion (Low CTE), a high glass transition temperature (High Tg), and a high modulus are used. (High Modulus) characteristics are required.

  On the other hand, various methods have been studied in order to improve the mechanical, electrical, and thermal characteristics of an insulating layer of a multilayer printed circuit board used in electronic devices due to the development of electronic devices.

  For example, in Patent Document 1, a thermosetting resin composition containing a cellulose derivative and a thermosetting compound is excellent in adhesion to a substrate, folding resistance, low warpage, solder heat resistance, electrical insulation, and the like. However, there is a disadvantage in that the printed circuit board having a higher density and higher functionality is not sufficient in the wiring of the printed circuit.

JP 2009-235171 A

  Therefore, the present inventors have developed a LiCl / DMAc (Lithium chloride / N, N'-dimethyl acetate) or LiCl / DMF (lithium chloride / dimethylformyl) cellulose solution (cellulose solution) and a liquid crystal oligomer (LiquidOl liquid crystal). ) Or a soluble thermosetting liquid crystal oligomer (LCTO) and an epoxy resin, the warpage of a product produced using an epoxy resin composition can be minimized. Low coefficient of thermal expansion (Low CTE), high glass transition temperature (High Tg) and high Confirmed to show a modulus (High the Modulus) characteristics, thereby forming the basis of the present invention.

  Accordingly, one object of the present invention is to provide an insulating epoxy resin composition having excellent thermal, mechanical and electrical properties.

  Another object of the present invention is to provide an insulating film manufactured with the epoxy resin composition and having improved thermal, mechanical and electrical properties.

  Still another object of the present invention is to provide a prepreg having improved thermal and mechanical properties by impregnating a base material with the epoxy resin composition.

  Still another object of the present invention is to provide a printed circuit board, preferably a multilayer printed circuit board, including the insulating film or the prepreg.

  Insulating epoxy resin composition according to the present invention for fulfilling one of the above objects (first invention) includes a LiCl / DMAc cellulose aqueous solution or a LiCl / DMF cellulose aqueous solution, a liquid crystal oligomer or a soluble thermosetting liquid crystal oligomer, An epoxy resin and an inorganic filler are included.

  In the first invention, the liquid crystal oligomer or the soluble thermosetting liquid crystal oligomer is represented by the following chemical formula 1, chemical formula 2, chemical formula 3, or chemical formula 4.

  (In said chemical formulas 1-4, a is an integer of 13-26, b is an integer of 13-26, c is an integer of 9-21, d is an integer of 10-30, e is an integer of 10-30. )

  1st invention WHEREIN: The said epoxy resin is represented by following Chemical formula 5 or Chemical formula 6, It is characterized by the above-mentioned.

  (In the chemical formula 5, R is an alkyl group having 1 to 20 carbon atoms, and n is an integer of 0 to 20)

  1st invention WHEREIN: The said epoxy resin composition contains the said cellulose aqueous solution 20-40 weight%, the said liquid crystal oligomer 13-25 weight%, the said epoxy resin 4-15 weight%, and the said inorganic filler 40-60 weight%. It is characterized by including.

  1st invention WHEREIN: The said cellulose aqueous solution contains 0.5-30 weight% of cellulose with respect to the said aqueous solution, It is characterized by the above-mentioned.

  In the first invention, the liquid crystal oligomer or the soluble thermosetting liquid crystal oligomer has a number average molecular weight of 2,500 to 6,500.

  In the first invention, the inorganic filler is silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, titanium. It is one or more selected from the group consisting of barium oxide, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate.

  1st invention WHEREIN: The diameter of the said inorganic filler is 0.008-10 micrometers, It is characterized by the above-mentioned.

  In the first invention, the epoxy resin composition comprises an amide curing agent, a polyamine curing agent, an acid anhydride curing agent, a phenol novolac curing agent, a polymercaptan curing agent, a tertiary amine curing agent, or an imidazole curing agent. It further comprises one or more selected curing agents.

  In the first invention, the epoxy resin composition is selected from a naphthalene type epoxy resin, a bisphenol A type epoxy resin, a phenol novolak epoxy resin, a cresol novolac epoxy resin, a rubber-modified epoxy resin, and a phosphorous type epoxy resin. It further includes one or more epoxy resins.

  In the first invention, the epoxy resin composition further includes one or more curing accelerators selected from metal-based curing accelerators, imidazole-based curing accelerators, and amine-based curing accelerators.

  In the first invention, the epoxy resin composition comprises a phenoxy resin, a polyimide resin, a polyamideimide (PAI) resin, a polyetherimide (PEI) resin, a polysulfone (PS) resin, a polyethersulfone (PES) resin, a polyphenylene ether ( It further includes at least one thermoplastic resin selected from PPE) resin, polycarbonate (PC) resin, polyether ether ketone (PEEK) resin, and polyester resin.

  The insulating film (2nd invention) for achieving the other objective of this invention is manufactured with the said epoxy resin composition.

  A prepreg (third invention) for achieving still another object of the present invention is produced by impregnating a base material with the epoxy resin composition.

  A printed circuit board, particularly a multilayer printed circuit board, for achieving still another object of the present invention includes an insulating film according to the second invention.

  A printed circuit board, particularly a multilayer printed circuit board, for achieving still another object of the present invention includes the prepreg according to the third invention.

  The insulating epoxy resin composition according to the present invention, the insulating film produced using the same, and the prepreg have a low thermal expansion coefficient, a high glass transition temperature, a high rigidity, heat resistance and mechanical strength. In a state where a low dielectric constant and hygroscopicity are basically ensured, a process property capable of forming a low roughness for forming a fine circuit pattern is also ensured.

It is sectional drawing of the copper clad laminated board which formed copper foil on the prepreg manufactured with the epoxy resin composition by this invention. It is sectional drawing of the normal printed circuit board to which the epoxy resin composition by this invention is applied.

  Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments with reference to the accompanying drawings. In this specification, it should be noted that when adding reference numerals to the components of each drawing, the same components are given the same number as much as possible even if they are shown in different drawings. I must. The terms “one side”, “other side”, “first”, “second” and the like are used to distinguish one component from another component, and the component is the term It is not limited by. Hereinafter, in describing the present invention, detailed descriptions of known techniques that may obscure the subject matter of the present invention are omitted.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  Referring to FIGS. 1 and 2, a printed circuit board according to a preferred embodiment of the present invention uses a copper clad laminate 30 in which a copper foil 20 is formed on a prepreg 10 made of an epoxy resin composition according to the present invention. Insulator 11 having a cavity, for example, an insulating film or prepreg 10, and other insulators 12 and / or 13 disposed on at least one of the upper and lower surfaces of the insulator 11, for example, a build-up layer Is included.

  The build-up layer may include an insulator 12 disposed on at least one of the upper surface and the lower surface of the insulator 11, and circuit layers 21 and 22 disposed on the insulator 13 and forming an interlayer connection.

  Here, the insulators 11, 12 and 13 can serve as a structural material for maintaining the rigidity of the package as well as providing insulation between circuit layers or between electronic components.

  At this time, in order to minimize the distortion of the substrate that occurs when reflow is performed in the process of mounting the electronic and electrical elements on the printed circuit board 100, preferably a multilayer printed circuit board, the insulators 11 and 12 of the present invention and 13 should have thermal, mechanical and electrical properties such as low coefficient of thermal expansion, high glass transition temperature, and high modulus.

  The insulators 11, 12 and 13 according to the present invention can form a low roughness for forming a fine circuit pattern in a state where a low dielectric constant and hygroscopicity are basically secured.

  Thus, according to the present invention, in order to ensure the excellent thermal, mechanical and electrical characteristics of the insulators 11, 12 and 13, the insulator is LiCl / DMAc (Lithium Corride / N, N '-Dimethyl acetate) or LiCl / DMF (Lithium chloride / dimethylformide) cellulose solution, liquid crystalline oligomer (LCO) and soluble thermosetting liquid crystal oligomer (Liquid crystalline epoxy, liquid crystalline epoxy) And an epoxy resin composition containing an inorganic filler. Optionally, the epoxy resin composition according to the present invention may further comprise a curing agent, a curing accelerator, further other epoxy resin, and / or other additives.

(LiCl / DMAc or LiCl / DMF cellulose solution)
Cellulose is a naturally occurring polymer formed by β (1 → 4) bonds of glucose (Glucose), which is a hexose sugar. Cellulose is a natural polymer obtained from most plants, and has a degree of polymerization of several thousand to several tens of thousands depending on the source material. Due to its chemical structure, it has strong hydrophilicity, and the hydroxy group at the 2nd carbon and the hydroxy group at the 6th carbon protruding outside the ring based on the 1st carbon that forms β bonds are mainly reactive with other substances. Priority is given, and in particular, -OH at the 6-position carbon has priority. In the present invention, the hydroxy group of cellulose reacts with an epoxy to cause a crosslinking reaction, and reacts with an amine group of LCO to form a chemical bond to improve the strength of the resin.

  The LiCl / DMAc or LiCl / DMF cellulose solution used in the present invention is a material used when forming a cellulose film using spin coating, and can provide a stable cellulose solution. It is presumed that the solution is formed by the release of hydrogen bonds by the catalytic reaction of LiCl and the polarity of DMAc or DMF. The strength of the resin is improved by the curing reaction in which the hydroxyl group of the cellulose chain reacts with the epoxy to form a crosslinking reaction and reacts with the amine of the liquid crystal oligomer main chain (Backbone). As a result, the curing density increases and a low coefficient of thermal expansion (Low CTE) characteristic can be realized. Thereby, the strength of the printed circuit board can also be improved.

  The said cellulose aqueous solution is used in 20-40 weight% with respect to the whole epoxy resin composition. When the amount used is less than 20% by weight, it becomes difficult to improve the resin strength and achieve a low coefficient of thermal expansion. When it exceeds 40% by weight, other components are relatively reduced. The glass transition temperature is only slightly improved and the mechanical properties are lowered.

  The cellulose content in the cellulose solution is about 0.5 to 30% by weight. When the content is less than 0.5% by weight, there is almost no effect of addition, and when it exceeds 30% by weight, it is difficult to form an insulating film because the entire solid content is large. Even if it is formed, it may be difficult to mold the member.

(Liquid crystal oligomer or soluble thermosetting liquid crystal oligomer)
The liquid crystal oligomer or soluble thermosetting liquid crystal oligomer used in the present invention (hereinafter sometimes referred to as “liquid crystal oligomer”) is a compound represented by the following chemical formula 1, chemical formula 2, chemical formula 3, or chemical formula 4. Can be.

  (In said chemical formulas 1-4, a is an integer of 13-26, b is an integer of 13-26, c is an integer of 9-21, d is an integer of 10-30, e is an integer of 10-30. )

  The liquid crystal oligomer represented by the chemical formula 1 or the chemical formula 2 or the soluble thermosetting liquid crystal oligomer represented by the chemical formula 3 or the chemical formula 4 has both ends of the main chain in order to improve the dielectric loss tangent and the dielectric constant. May include a naphthalene group for crystallinity and a phosphorus component that imparts flame retardancy as in Chemical Formula 2 or Chemical Formula 4.

  In more detail, the liquid crystal oligomer or the soluble thermosetting liquid crystal oligomer may be thermally cured with an epoxy or bismaleimide containing a hydroxyl group or a nadimide group at the terminal and added. It can also react with the hydroxy groups of the formed cellulose. The oligomer includes an amide group that imparts solubility and a naphthalene group that imparts liquid crystallinity, and the compounds represented by Chemical Formula 2 and Chemical Formula 4 include a phosphorus component to achieve flame retardancy. . In the case of an amide group, it can react with the added hydroxy group of cellulose. “A”, “b”, “c”, “d” and “e” in the above chemical formula mean the molar ratio of repeating units, and are determined by the content of the starting material.

  The number average molecular weight of the liquid crystal oligomer is preferably 2,500 to 6,500 g / mol, more preferably 3,000 to 6,000 g / mol, and still more preferably 3,000 to 5,000 g / mol. When the number average molecular weight of the liquid crystal oligomer is less than 2,500 g / mol, the mechanical properties deteriorate, and when it exceeds 6,500 g / mol, the solubility decreases.

  The amount of the liquid crystal oligomer used is preferably 13 to 25% by weight, and more preferably 15 to 20% by weight. When the amount used is less than 13% by weight, the reduction of the thermal expansion coefficient and the improvement of the glass transition temperature are negligible, and when it exceeds 25% by weight, the mechanical properties are lowered.

(Epoxy resin)
The epoxy resin composition by this invention contains an epoxy resin in order to improve the handleability as an adhesive film of the resin composition after drying. The epoxy resin is not particularly limited, but means that one or more epoxy groups are contained in the molecule, preferably means that two or more epoxy groups are contained in the molecule, and more preferably, It means that 4 or more epoxy groups are contained in the molecule.

  The epoxy resin used in the present invention preferably includes a naphthalene group as shown in the following chemical formula 5 or an aromatic amine type as shown in the following chemical formula 6.

  (In the chemical formula 5, R is an alkyl group having 1 to 20 carbon atoms, and n is an integer of 0 to 20)

  However, the epoxy resin used in the present invention is not particularly limited to the epoxy resin represented by the chemical formula 5 or the chemical formula 6, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin. , Phenol novolac type epoxy resin, alkylphenol novolak type epoxy resin, cresol novolac epoxy resin, biphenyl type epoxy resin, aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, phenols and phenolic Condensation products with aromatic aldehydes having hydroxyl groups, biphenyl aralkyl type epoxy resins, fluorene type epoxy resins, xanthene type epoxy resins, triglycidyl isoforms Cyanurate, and rubber-modified epoxy resin and phosphorus (phosphorous) epoxy resins can be used. You may use the said epoxy resin 1 type or in mixture of 2 or more types. Preferably, at least one selected from naphthalene-based epoxy resins, bisphenol A-type epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, rubber-modified epoxy resins, and phosphorus-based epoxy resins can be used.

  The use amount of the epoxy resin is preferably 4 to 15% by weight. When the use amount is less than 4% by weight, the handleability is deteriorated. Since the addition amount is relatively reduced, the dielectric loss tangent, dielectric constant and thermal expansion coefficient are hardly improved.

(Inorganic filler)
The epoxy resin composition according to the present invention includes an inorganic filler in order to reduce the coefficient of thermal expansion (CTE) of the epoxy resin. The inorganic filler is for lowering the thermal expansion coefficient, and varies depending on required properties, but is included in an amount of 40 to 60% by weight based on the resin composition in consideration of the use of the resin composition. It is preferable. When the content is less than 40% by weight, the dielectric loss tangent is low and the coefficient of thermal expansion is high, and when it exceeds 60% by weight, the adhesive strength is lowered.

  Specific examples of the inorganic filler used in the present invention include silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, Examples thereof include aluminum borate, barium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate, and these can be used alone or in combination of two or more. . In particular, silica having a low dielectric loss tangent is preferable.

  The inorganic filler can be used by being dispersed in a size of several nanometers to several tens of micrometers or mixed without being dispersed. When the average particle diameter of the inorganic filler exceeds 10 μm, it is difficult to stably form a fine pattern when forming a circuit pattern on the conductor layer. Therefore, the average particle diameter is preferably 10 μm or less. The inorganic filler is preferably surface-treated with a surface treatment agent such as a silane coupling agent in order to improve moisture resistance. More preferably, silica having a diameter of 0.008 to 5 μm is preferable.

(Curing agent)
On the other hand, according to the present invention, it is possible to use a curing agent selectively, and it can be used as long as it can be used for thermosetting an epoxy resin, and is not particularly limited.

  Specifically, amide-based curing agents such as dicyandiamide; polyamine-based curing agents such as diethylenetriamine, triethylenetetraamine, N-aminoethylpiperazine, diaminodiphenylmethane, adipic acid dihydrazide; and pyromellitic anhydride as acid anhydride curing agent , Benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitic anhydride, glycerol tristrimellitic anhydride, maleic methylcyclohexene tetracarboxylic anhydride, etc .; phenol novolac type curing agent; trioxane tritylene as polymercaptan curing agent Mercaptans, etc .; benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, etc. as tertiary amine curing agents; 2-ethyl- as imidazole curing agents -Methylimidazole, 2-methylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenylimidazole, 2 -Phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and curing agents Can be used alone or in admixture of two or more. In particular, dicyandiamide is preferable in terms of physical properties. The amount of the curing agent used is within a range known to those skilled in the art, for example, within a range of 0.1 to 1 part by weight with respect to 100 parts by weight of the mixture of the liquid crystal oligomer and the epoxy resin. Can be selected and used in consideration of the curing rate.

(Curing accelerator)
The epoxy resin composition of the present invention can selectively cure the epoxy resin of the present invention selectively by further including a curing accelerator. Examples of the curing accelerator used in the present invention include metal-based curing accelerators, imidazole-based curing accelerators, amine-based curing accelerators, etc., and these are usually used in the industry in combination of one or more. The amount of can be added and used.

  Although it does not restrict | limit especially as said metal type hardening accelerator, The organometallic complex or organometallic salt of metals, such as cobalt, copper, zinc, iron, nickel, manganese, tin, is mentioned. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetyl. Organic zinc complexes such as acetonate, organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate . Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate. As the metal-based curing accelerator, in terms of curability and solvent solubility, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, zinc (II) acetylacetonate, zinc naphthenate, iron (III) Acetylacetonate is preferable, and cobalt (II) acetylacetonate and zinc naphthenate are particularly preferable. A metal type hardening accelerator can be used 1 type or in combination of 2 or more types.

  The imidazole curing accelerator is not particularly limited, but 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2 -Dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2 -Methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellit, 1 - Noethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-un Decylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4 -Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2 -Phenyl-4-methyl-5hydroxymethylimidazole, 2,3-dihydroxy-1H-pyrrolo [1,2-a] benzimidazole, 1-dodecyl 2-methyl-3-benzyl-imidazolium chloride, 2-methyl-imidazoline, imidazole compounds such as 2-phenyl-imidazoline and imidazole compounds and adducts of epoxy resins. One or two or more imidazole curing accelerators can be used in combination.

  The amine curing accelerator is not particularly limited, but trialkylamine such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 1, Examples thereof include amine compounds such as 8-diazabicyclo (5,4,0) -undecene (hereinafter, DBU). An amine type hardening accelerator can be used 1 type or in combination of 2 or more types.

(Thermoplastic resin)
The epoxy resin composition of the present invention can selectively contain a thermoplastic resin in order to improve the film properties of the resin composition or to improve the mechanical properties of the cured product. Examples of thermoplastic resins include phenoxy resin, polyimide resin, polyamideimide (PAI) resin, polyetherimide (PEI) resin, polysulfone (PS) resin, polyethersulfone (PES) resin, polyphenylene ether (PPE) resin, Polycarbonate (PC) resin, polyether ether ketone (PEEK) resin, polyester resin, etc. are mentioned. These thermoplastic resins are used alone or in combination of two or more.

  The weight average molecular weight of the thermoplastic resin is preferably in the range of 5,000 to 200,000. When the weight average molecular weight of the thermoplastic resin is less than 5,000, the effect of improving the film formability and mechanical strength is not sufficiently exhibited. When the weight average molecular weight is greater than 200,000, cellulose, a liquid crystal oligomer and an epoxy resin Are not sufficient, the surface irregularities after curing become large, and it is difficult to form a high-density fine pattern.

  When a thermoplastic resin is blended in the epoxy resin composition of the present invention, the content of the thermoplastic resin in the resin composition is not particularly limited, but is 0.1 with respect to 100% by weight of the nonvolatile content in the resin composition. -10 wt% is preferable, and 1-5 wt% is more preferable. When the content of the thermoplastic resin is less than 0.1% by weight, the effect of improving the film formability and mechanical strength is not exhibited. When the content exceeds 10% by weight, the melt viscosity is increased and wet. The surface roughness of the insulating layer after the roughening process is increased.

  On the other hand, the epoxy resin composition according to the present invention, which has a viscosity of 700 to 1500 cps, is suitable for manufacturing an insulating film and has a characteristic of maintaining an appropriate viscosity at room temperature. The viscosity of the epoxy resin composition of the present invention can be adjusted by changing the content of a solvent (for example, DMAc or DMF). When the viscosity of the epoxy resin composition is out of the above range, it is difficult to form an insulating film, and even if formed, it may be difficult to mold a member.

  Moreover, peel strength shows 1.0 kN / m or more when a 12-micrometer copper foil is used in the state of an insulating film. The insulating film manufactured with the epoxy resin according to the present invention has a coefficient of thermal expansion (CTE) measured at a temperature range of 50 to 150 ° C. of less than 35 ppm / ° C. and a coefficient of thermal expansion (CTE) measured at a glass transition temperature or higher. It has a value of less than 80 ppm / ° C.

  The tensile strength is 9.2 or more, preferably 10 or more, and the glass transition temperature (Tg) is 200 to 300 ° C., preferably 210 to 270 ° C.

  In addition, the present invention may further include other leveling agents and / or flame retardants known to those skilled in the art within the technical idea of the present invention as necessary.

  The epoxy resin composition of the present invention can be produced into a semi-solid dry film by any common method known in the art. For example, a roll coater (Roll Coater) or a curtain coater (Curtain Coater) or the like is used to produce a film and dry it. Then, this is applied to the substrate, and an insulating layer ( Or an insulating film) or a prepreg. Such an insulating film or prepreg has a low coefficient of thermal expansion (CTE) of 35 ppm / ° C. or less.

  Thus, after impregnating the epoxy resin composition according to the present invention into a substrate such as glass fiber, it is cured to produce a prepreg, and a copper foil is laminated on the copper-clad laminate as shown in FIG. A plate (CCL: copper clad laminate) is obtained.

  In addition, the insulating film manufactured with the epoxy resin composition according to the present invention is laminated on the CCL used as an inner layer at the time of manufacturing the multilayer printed circuit board, and used for manufacturing the multilayer printed circuit board as shown in FIG. For example, after laminating an insulating film manufactured with the epoxy resin composition on a patterned inner layer circuit board, curing it at a temperature of 80 to 110 ° C. for 20 to 30 minutes and performing a desmear process, a circuit layer A multilayer printed circuit board can be manufactured by forming the above by an electroplating process.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the scope of the present invention is not limited to the following examples.

(Production example)
[Production of liquid crystal oligomer]
In a 20 L glass reactor, 218.26 g (2.0 mol) of 4-aminophenol, 415.33 g (2.5 mol) of isophthalic acid, 276.24 g (2.0 mol) of 4-hydroxybenzoic acid, 6-hydroxy-2 -282.27 g (1.5 mol) of naphthoic acid, 9,10-dihydroxy-9oxa-10-phosphaphenanthrene-10-oxide (DOPO; 9,10-Dihydro-9-oxa-10-phosphophenanthrene-10- oxide) 648.54 g (2.0 mol) and acetic anhydride 1531.35 g (15.0 mol) were added. After sufficiently replacing the inside of the reactor with nitrogen gas, the temperature in the reactor was raised to 230 ° C. under a nitrogen gas stream and refluxed for 4 hours while maintaining the temperature inside the reactor at that temperature. After further adding 188.18 g (1.0 mol) of 6-hydroxy-2-naphthoic acid for end-capping, the reaction by-product acetic acid and unreacted acetic anhydride are removed to obtain a molecular weight of about 4500. A liquid crystal oligomer represented by 2 was produced.

Example 1
[Manufacture of varnish and film using LiCl / DMAc cellulose solution]
A liquid crystal oligomer solution containing cellulose is produced by adding 50 g of the liquid crystal oligomer containing a hydroxy group produced in Production Example 1 to 83 g of a LiCl / DMAc cellulose solution (cellulose content: 10 wt%). To this, 107.09 g of silica filler slurry (silica content 78.13 wt%) is added and stirred for 30 minutes. To this, 25 g of epoxy resin Araldite MY-721 (Huntsmann) and 0.33 g of dicyandiamide (curing catalyst) are added and stirred for 2 hours. This is applied to a shiny surface of copper foil to a thickness of 100 μm by a doctor blade method to produce a film. The manufactured film is dried at room temperature for 2 hours, dried in a vacuum oven at 80 ° C. for 1 hour, and further dried at 110 ° C. for 1 hour to be in a semi-cured state (B-stage). This is completely cured using a vacuum pressure. At this time, the maximum temperature was 230 ° C. and the maximum pressure was 2 MPa.

(Example 2)
[Manufacture of varnish and film using LiCl / DMAc cellulose solution]
50 g of the liquid crystal oligomer containing a hydroxy group produced in Production Example 1 is added to 42 g of LiCl / DMAc cellulose solution (cellulose content 10 wt%), and 10 g of DMAc is added to produce a liquid crystal oligomer solution containing cellulose. To this, 107.09 g of silica filler slurry (silica content 78.13 wt%) is added and stirred for 30 minutes. To this, 25 g of epoxy resin Araldite MY-721 (Huntsmann) and 0.33 g of dicyandiamide as a curing catalyst are added and stirred for 2 hours. This is applied to a shiny surface of copper foil to a thickness of 100 μm by a doctor blade method to produce a film. The manufactured film is dried at room temperature for 2 hours, dried in a vacuum oven at 80 ° C. for 1 hour, and further dried at 110 ° C. for 1 hour to make a semi-cured state. This is fully cured using vacuum pressure. At this time, the maximum temperature was 230 ° C. and the maximum pressure was 2 MPa.

(Comparative Example 1)
[Production of varnish containing liquid crystal oligomer and production of film]
A liquid crystal oligomer solution is prepared by adding 50 g of the liquid crystal oligomer prepared in Preparation Example 1 to 50 g of N, N′-dimethylacetamide (DMAc). To this, 107.09 g of silica filler slurry (silica content 78.13 wt%) is added and stirred for 30 minutes. To the mixture of the liquid crystal oligomer solution and the silica filler slurry, 33.3 g of Araldite MY-721 (Huntsmann) as an epoxy resin and 0.33 g of dicyandiamide as a curing catalyst are added and stirred for 2 hours. This is applied to a shiny surface of copper foil to a thickness of 100 μm by a doctor blade method to produce a film. The manufactured film is dried at room temperature for 2 hours, dried in a vacuum oven at 80 ° C. for 1 hour, and further dried at 110 ° C. for 1 hour to be in a semi-cured state (B-stage). This is fully cured using vacuum pressure. At this time, the maximum temperature was 230 ° C. and the maximum pressure was 2 MPa.

(Evaluation of thermal characteristics)
The thermal expansion coefficient (CTE) of the test piece of the insulation film manufactured by the Example and the comparative example was measured using a thermal analyzer (TMA; Thermo mechanical Analyzer) at a temperature range of 50 to 150 ° C. (a1) and glass transition. Measured above temperature (a2). The glass transition temperature (Tg) is 270 ° C. (first measurement) by increasing the temperature of a thermal analyzer (TA Instruments TMA 2940) at 10 ° C./min in a nitrogen atmosphere by differential scanning calorimetry (DSC). ) And 300 ° C. (second cycle). Furthermore, the tensile strength was measured by dynamic mechanical analysis (DMA) and is shown in Table 1 below.

  As can be seen from Table 1, the insulating films (Example 1 and Example 2) manufactured with the epoxy resin composition according to the present invention have a relatively low coefficient of thermal expansion and high tensile strength compared to the film of Comparative Example 1. Has strength and high glass transition temperature (Tg).

  As described above, the present invention has been described in detail based on the specific embodiments. However, the present invention is only for explaining the present invention, and the present invention is not limited thereto. It will be apparent to those skilled in the art that modifications and improvements within the technical idea of the present invention are possible.

  All simple variations and modifications of the present invention belong to the scope of the present invention, and the specific scope of protection of the present invention will be apparent from the appended claims.

  The present invention is applicable to an insulating epoxy resin composition, an insulating film, a prepreg, and a printed circuit board.

DESCRIPTION OF SYMBOLS 10 Prepreg 11, 12, 13 Insulator 20 Copper foil 21, 22 Circuit pattern 30 Copper clad laminated board 100 Printed circuit board

Claims (16)

LiCl / DMAc cellulose aqueous solution or LiCl / DMF cellulose aqueous solution,
A liquid crystal oligomer or a soluble thermosetting liquid crystal oligomer;
Epoxy resin,
An insulating epoxy resin composition comprising an inorganic filler. The insulating epoxy resin composition according to claim 1, wherein the liquid crystal oligomer or the soluble thermosetting liquid crystal oligomer is represented by the following chemical formula 1, chemical formula 2, chemical formula 3, or chemical formula 4.

(In said chemical formulas 1-4, a is an integer of 13-26, b is an integer of 13-26, c is an integer of 9-21, d is an integer of 10-30, e is an integer of 10-30. ) The insulating epoxy resin composition according to claim 1, wherein the epoxy resin is represented by the following chemical formula 5 or chemical formula 6.

(In the chemical formula 5, R is an alkyl group having 1 to 20 carbon atoms, and n is an integer of 0 to 20)

  The epoxy resin composition includes 20 to 40% by weight of the aqueous cellulose solution, 13 to 25% by weight of the liquid crystal oligomer, 4 to 15% by weight of the epoxy resin, and 40 to 60% by weight of the inorganic filler. The insulating epoxy resin composition according to claim 1.   The insulating epoxy resin composition according to claim 1, wherein the cellulose aqueous solution contains 0.5 to 30% by weight of cellulose.   The insulating epoxy resin composition according to claim 1, wherein the liquid crystal oligomer or the soluble thermosetting liquid crystal oligomer has a number average molecular weight of 2,500 to 6,500.   The epoxy resin composition includes at least one selected from a naphthalene-based epoxy resin, a bisphenol A-type epoxy resin, a phenol novolac epoxy resin, a cresol novolac epoxy resin, a rubber-modified epoxy resin, and a phosphorous epoxy resin. The insulating epoxy resin composition according to claim 1, further comprising an epoxy resin.   The epoxy resin composition is one selected from an amide curing agent, a polyamine curing agent, an acid anhydride curing agent, a phenol novolac curing agent, a polymercaptan curing agent, a tertiary amine curing agent, or an imidazole curing agent. The insulating epoxy resin composition according to claim 1, further comprising the above curing agent.   The inorganic filler is silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, titanate The insulating epoxy resin composition according to claim 1, wherein the composition is one or more selected from the group consisting of calcium, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate. .   2. The insulating epoxy resin composition according to claim 1, wherein the inorganic filler has a diameter of 0.008 to 10 μm.   The epoxy resin composition further includes one or more curing accelerators selected from metal-based curing accelerators, imidazole-based curing accelerators, and amine-based curing accelerators. Insulating epoxy resin composition.   The epoxy resin composition includes phenoxy resin, polyimide resin, polyamideimide (PAI) resin, polyetherimide (PEI) resin, polysulfone (PS) resin, polyethersulfone (PES) resin, polyphenylene ether (PPE) resin, polycarbonate The insulating epoxy resin composition according to claim 1, further comprising one or more thermoplastic resins selected from (PC) resins, polyether ether ketone (PEEK) resins, and polyester resins.   The insulating film manufactured with the epoxy resin composition of Claim 1.   A prepreg produced by impregnating a base material with the epoxy resin composition according to claim 1.   A printed circuit board comprising the insulating film according to claim 13.   A printed circuit board comprising the prepreg according to claim 14.

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