KR20090064288A - Printed circuit board composition and printed circuit board using the same - Google Patents

Abstract

One embodiment of the present invention is a printing comprising a polyamic acid, a liquid crystal polymer (LCP) or a liquid crystalline thermoset oligomer (LCT) having a cross-linking functional group introduced to at least one of the socks end of the main chain A composition for forming a circuit board and a printed circuit board using the same. The composition for forming a printed circuit board according to one embodiment of the present invention may be advantageously applied as a material of a next generation substrate that is light and short in size due to its excellent mechanical and thermal properties.

Description

Composition for forming printed circuit board and printed circuit board using the same {Composition for forming Printed Circuit Board and Printed Circuit Board using the same}

The present invention relates to a composition for forming a printed circuit board and a printed circuit board using the same, and more particularly, to a polyamic acid, a liquid crystalline polymer, or a liquid crystal thermoset oligomer having a crosslinking functional group introduced into at least one of the sock ends of the main chain. A composition for forming a printed circuit board and a printed circuit board using the same.

As electronic devices become more complex, much of the wiring has been replaced by circuit boards, and as the electronic devices become thin and short, the flexible printed circuits (FPC) of conventional printed circuit boards (FPC) have been developed. It is rapidly being replaced by a circuit board. In particular, the development of portable electronic devices such as mobile phones, laptops, camcorders, etc. is expanding the market for flexible substrates.

Currently, bismaleimide-triazine (BT) and glass epoxy (eg FR-4) materials are mainly used as substrate materials. These materials have excellent mechanical properties and low dielectric properties, which are required for future packaging technologies. Since it is difficult to satisfy high heat resistance, low thermal expansion, and low moisture absorption characteristics, development of a new substrate material having characteristics required for the next generation substrate is required.

The present invention is to meet the above technical needs, one embodiment of the present invention is to provide a printed circuit board forming composition that can improve the mechanical and thermal properties when used as a substrate material.

Another embodiment of the present invention is to provide a film or prepreg prepared using the composition.

Another embodiment of the present invention is to provide a printed circuit board having excellent heat resistance using the composition for forming a printed circuit board, reduced thermal expansion, and excellent mechanical properties.

One embodiment of the present invention is for forming a printed circuit board comprising a polyamic acid, a liquid crystalline polymer or a liquid crystal thermoset oligomer having a structure of the formula (1) in which a cross-linking functional group is introduced into one or more of the socks end of the main chain It relates to a composition.

Wherein A is represented by the following formula (2),

when n is 2 or more, each A is the same as or different from each other,

Each of Z ₁ and Z ₂ is the same as or different from each other, and is a monovalent crosslinking functional group having a carbon-carbon double bond,

Y ₁ is a divalent aliphatic or aromatic organic group,

n is an integer of 1 or more and 1,000 or less;

Wherein X is a tetravalent aliphatic or aromatic organic group,

Y ₂ is a divalent aliphatic or aromatic organic group, and Y ₁ and Y ₂ may be the same or different.

Another embodiment of the present invention is a film or a composition prepared by casting a composition comprising a polyamic acid, a liquid crystalline polymer or a liquid crystal thermoset oligomer and an organic solvent having a cross-linking functional group introduced to at least one of the socks end of the main chain to a reinforcing material It relates to a prepreg produced by impregnation.

Still other embodiments of the present invention relate to a printed circuit board including the prepreg.

Printed circuit board forming compositions of various embodiments of the present invention can be advantageously applied to the material of the next-generation substrate that is light and short due to excellent mechanical and thermal properties.

Hereinafter, the present invention will be described in more detail.

The composition for forming a printed circuit board according to one embodiment of the present invention includes a polyamic acid having a crosslinked functional group introduced into at least one sock end of the main chain, a liquid crystalline polymer or a liquid crystal thermoset oligomer, and an organic solvent. In other words, the composition for forming a printed circuit board is a blend of a polyamic acid having a crosslinked functional group introduced at its end in order to realize high heat resistance and low thermal expansion in a liquid crystal polymer or liquid crystal thermoset oligomer for a substrate that is poor in heat resistance and low thermal expansion. When the composition is thinned and then cured at high temperature, film properties of high heat resistance and low thermal expansion may be realized.

The substrate using the composition for forming a printed circuit board of one embodiment of the present invention has a glass transition temperature of 250 ° C. or higher and a coefficient of thermal expansion (CTE) of 20 ppm or less. Can be used as the substrate material required.

The polyamic acid may be represented by the following formula (1).

[Formula 1]

Wherein A is represented by the following formula (2),

when n is 2 or more, each A is the same as or different from each other,

Each of Z ₁ and Z ₂ is the same as or different from each other, and is a monovalent crosslinking functional group having a carbon-carbon double bond,

Y ₁ is a divalent aliphatic or aromatic organic group,

n is an integer of 1 or more and 1,000 or less;

[Formula 2]

Wherein X is a tetravalent aliphatic or aromatic organic group,

Y ₂ is a divalent aliphatic or aromatic organic group, and Y ₁ and Y ₂ may be the same or different.

The number average molecular weight of the polyamic acid is not particularly limited, but may be, for example, in the range of 1,000 to 90,000.

In the composition of one embodiment of the present invention, the mixing ratio of the polyamic acid to the liquid crystalline polymer or the liquid crystal thermoset oligomer is preferably 1: 9 to 9: 1. When the polyamic acid is added in an excessive amount, the thermal characteristic improvement effect may be insufficient.

A general method of preparing the polyamic acid is to dissolve a diamine compound in an aprotic solvent such as NMP in a reactor and to fully polymerize the dianhydride compound for 2 hours, and then double competition or triple bond. A monoamine compound or a monoanhydride compound having the same may be added and the reaction proceeds for at least 16 hours to obtain a polyamic acid solution having a crosslinked functional group introduced at the terminal.

Specific examples of X in Formula 1

Tetravalent organic groups selected from the group consisting of, but are not necessarily limited to these.

In Formula 1, each of Y ₁ and Y ₂ are the same as or different from each other,

It may be a monovalent organic group selected from the group consisting of.

Z ₁ and Z ₂ are each independently

Monovalent organic group selected from the group consisting of.

Specific examples of the polyamic acid may be represented by the following Chemical Formula 3 or Chemical Formula 4, but are not necessarily limited thereto.

Wherein k is 1 to 1,000,

Wherein l is 1 to 500 and m is 1 to 900.

The liquid crystalline polymer includes at least one selected from the group consisting of liquid crystalline polyester, liquid crystalline polyamide, liquid crystalline polyester amide, liquid crystalline polyester imide, and liquid crystalline polyamide imide, but is not limited thereto. It doesn't happen.

An example of the liquid crystal thermoset oligomer may be represented by the following Formula 5.

Where

Each Y ₃ , Y ₄ and Y ₅ is the same or different from each other and is a divalent aliphatic or aromatic organic group comprising at least one structure selected from the group consisting of esters, amides, ethers and imides,

Ar comprises at least one aromatic structural unit selected from the group represented by the following formula (6), and each aromatic ring is directly connected or connected through at least one structure selected from the group consisting of esters, amides, ethers, and imides Is a divalent aromatic organic group,

Each of Z ₃ and Z ₄ is the same as or different from each other, a monovalent organic group having a double bond or a triple bond,

n is an integer of 1 or more and 10,000 or less.

In Formula 5, when n is 2 or more, each [Ar-Y-] structure may be the same as or different from each other. The aromatic ring of Ar may be substituted with an amide group, ester group, carboxyl group, alkoxy group, aryl group or fluoromethyl group. The liquid crystal thermoset oligomer may have the same or different cross-linking groups introduced at one or more of both ends of the main chain. Such a crosslinking functional group may include an acetylene, cyanide, maleimide, or namidide group as described in Chemical Formula 1.

Examples of the liquid crystal thermoset oligomer having a crosslinked functional group introduced into at least one of the sock ends of the main chain include, but are not necessarily limited to, a liquid crystal oligomer having a structure of Formula 7 or Formula 8 below.

Wherein m is 1 to 50 and n is 1 to 50.

Wherein m is 1 to 50 and n is 1 to 50.

The method for preparing the liquid crystal thermoset oligomer is not particularly limited, and for example, may be prepared by solution polymerization or bulk polymerization. Solution polymerization and bulk polymerization can be carried out in one reaction tank equipped with suitable stirring means. Specifically, it may be prepared by reacting one or more aromatic, heterocyclic or aliphatic dicarboxylic acids, aromatic, heterocyclic or aliphatic diols, hetero rings or aliphatic diamines, hydroxybenzoic acid and aminobenzoic acid.

As an example of the solution polymerization method, first, isophthaloyl chloride, aminophenol, 2,6-dihydroxynaphthalene, and triethylamine are added to a reactor. The reaction proceeds while stirring at room temperature. After a certain time, 4-maleimide-benzoyl chloride was further added to the terminal reactor to react to obtain a liquid crystal thermoset, and then separated and purified to form a liquid crystal thermoset oligomer having crosslinked functional groups introduced into at least one of both ends of the main chain. Can be prepared.

On the other hand, when manufacturing a liquid crystal thermoset oligomer by bulk polymerization, after adding isophthalic acid, aminophenol, 2-hydroxy-6-naphthoic acid, and acetic anhydride to a reactor, the temperature was gradually raised to 150 degrees while stirring. After reacting for 3 hours while refluxing. Subsequently, effluent by-product acetic acid and acetic anhydride are removed and then 4-hydroxybenzoic acid is further added, and the reaction is carried out by raising the temperature to 320 degrees. In this way, oligomer liquid crystals having alcohol groups at both terminals can be synthesized. When an oligomeric liquid crystal having an alcohol group at the end of the sock is obtained, a compound capable of adding maleimide, namidide, cyanide or acetylene after dissolving the oligomeric liquid crystal in a solvent (for example, DMF) as in Scheme 1 below (for example, When 4-maleimido-benzoyl chloride) is added and reacted, a liquid crystal thermoset oligomer to which acetylene, maleimide, cyanide or namidide group is added to the end of the molecule can be obtained.

Examples of aromatic dicarboxylic acids for providing a carboxyl group in such structural units include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 4,4'-biphenyl Dicarboxylic acid, methyl terephthalic acid, methylisophthalic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenyl ketone-4,4'-dica Carboxylic acid, 2,2'-diphenylpropane-4,4'-dicarboxylic acid, and the like. These may be used alone or in combination of two or more.

Examples of the ester-forming derivatives of the aromatic hydroxycarboxylic acid and the aromatic amine having a hydroxyl group for providing a phenolic hydroxyl group include ester-exchange when the phenolic hydroxyl group forms an ester group together with the carboxylic acid. Compounds which are converted into derivatives which form ester groups by reaction. Examples of amide-forming derivatives of aromatic amines having aromatic diamines and hydroxyl groups for providing amide groups include compounds in which an amino group is formed with an carboxylic acid to form an amide group by a condensation reaction, thereby forming an amide group. do.

The liquid crystal thermoset oligomer may include 10-50 mol% of the soluble structural units derived from the aromatic amine based on the total of all the structural units. When the content of the soluble structural unit is less than 10 mol%, the solubility improvement effect in the solvent may be insignificant. In contrast, when the content of the soluble group exceeds 50 mol%, the hydrophilicity is increased to reduce the hygroscopic resistance. This can happen.

In the composition for forming a printed circuit board according to one embodiment of the present invention, the content of the soluble structural unit may include a desired level of soluble structure in the liquid crystal thermoset oligomer by controlling the monomer content added during the reaction. The content of the soluble structural unit can be adjusted by changing the size, mass, properties and chemical composition of the soluble structural unit.

The composition for forming a printed circuit board according to one embodiment of the present invention includes an organic solvent for solvent casting to prevent mechanical property deterioration due to anisotropy of liquid crystal.

The kind of the organic solvent is not particularly limited, but for example, N, N-dimethylacetamide, N-methylpyrrolidone (NMP), N-methylcaprolactam, N, N-dimethylformamide, N, N Consisting of diethylformamide, N, N-diethylacetamide, N-methyl propionamide, dimethylsulfoxide, γ-butyl lactone, dimethylimidazolidinone, tetramethylphosphoric amide and ethylcellosolve acetate One selected from the group can be used, and two or more kinds of mixed solvents can be optionally used.

The composition for forming a printed circuit board according to various embodiments of the present invention may be composed of a polyamic acid, a liquid crystalline polymer and an organic solvent having a crosslinking functional group introduced into at least one of the sock ends of the main chain, or may be crosslinked with at least one of the sock ends of the main chain. Polyamic acid, liquid crystal thermoset oligomer, and organic solvent into which functional groups are introduced. The composition for forming a printed circuit board may include 5 parts by weight to 100 parts by weight of polyamic acid and 5 to 100 parts by weight of a liquid crystalline polymer or a liquid crystal thermoset based on 100 parts by weight of an organic solvent.

The composition of another embodiment of the present invention may further include an inorganic filler in addition to the polyamic acid and the liquid crystalline polymer or the liquid crystal thermoset oligomer having a crosslinked functional group introduced into at least one of the sock ends of the main chain. Examples of such inorganic fillers are in the group consisting of silica, aluminum borate, potassium titanate, magnesium sulfate, silicon carbide, zinc oxide, silicon nitride, silicon dioxide, aluminum titanate, barium titanate, barium strontium titanate and aluminum oxide It includes one or more selected, but is not necessarily limited to these.

The printed circuit board forming composition of one embodiment of the present invention may further include one or more additives such as fillers, softeners, plasticizers, lubricants, antistatic agents, colorants, antioxidants, heat stabilizers, light stabilizers, and UV absorbers as needed. Can be. Examples of the filler may include organic fillers such as epoxy resin powder, melamine resin powder, urea resin powder, benzoguanamine resin powder and styrene resin.

The printed circuit board forming composition of one embodiment of the present invention can be used as a next-generation packaging material that requires high heat resistance and low thermal expansion characteristics. The composition for forming a printed circuit board of one embodiment of the present invention may be molded into a substrate or form a varnish for impregnation or coating. The composition of one embodiment of the present invention can be used as a laminate, a printed board, each layer of a multilayer substrate, a copper foil with a resin, a copper clad laminate, a polyimide film, a film for TAB and a prepreg, but Use of the composition for forming a printed circuit board of one embodiment is not limited thereto.

In order to use the composition of one embodiment of the present invention as a material such as a substrate, a composition including a polyamic acid, a liquid crystalline polymer or a liquid crystal thermoset, and an organic solvent may be cast on a substrate to form a thin film, and then manufactured by curing at high temperature. . A printed circuit board forming composition of one embodiment of the present invention is a mixture of a polyamic acid having a cross-linking functional group at the end of a liquid crystalline polymer or a liquid crystal thermoset, and hardened when fabricated into a substrate using such a composition. By introducing a polyimide having a crosslinked structure, mechanical properties and thermal properties can be significantly improved.

The composition for forming a printed circuit board of various embodiments of the present invention may be prepared by any method. For example, a polyamic acid having a cross-linking functional group introduced into at least one of the sock ends of the main chain: and a liquid crystalline polymer or a liquid crystal thermoset oligomer is dissolved in an organic solvent to prepare a mixed solution. Thermal curing at temperature imidates the polyamic acid and converts it to modified polyimide. When preparing the mixed solution, polyamic acid to liquid crystalline polymer or liquid crystal thermoset may be mixed in a mixing ratio of 1: 9 to 9: 1.

Other embodiments of the invention relate to films made by solvent casting the compositions of various embodiments of the invention or to prepregs made by impregnating such a composition with a reinforcement. The reinforcing material is not particularly limited, but examples thereof include woven glass fibers, woven alumina glass fibers, glass fiber nonwoven fabrics, cellulose nonwoven fabrics, woven carbon fibers, and polymeric fabrics.

The prepreg manufacturing method includes a method of impregnating a glass fiber with a composition for forming a printed circuit board and removing an organic solvent. As a method of impregnating the glass fiber composition for forming a printed circuit board, there are dip coating, roll coating, and the like, and other conventional impregnation methods can be used.

On the other hand, in the case of manufacturing in the form of a copper clad laminate, the composition for forming a printed circuit board may be prepared by a method of coating on a copper foil or cast on a copper foil, heat treatment after removing the solvent. Solvent removal is preferably done by evaporating the solvent, examples of how to evaporate the solvent may include heating under reduced pressure, ventilation, and the like.

Examples of the method of applying the composition for forming a printed circuit board include, but are not limited to, roller coating, dip coating, spray coating, spinner coating, curtain coating, slot coating and screen printing. no.

In the printed circuit board forming composition of one embodiment of the present invention, it is preferable to filter by using a filter or the like to remove fine external substances contained in the solution before being coated or cast on the copper foil.

Still other embodiments of the present invention relate to a printed circuit board having the prepreg. For example, a printed circuit board is laminated with an inner layer substrate on which a circuit is made, the prepreg and copper foil according to design specifications, and then put into a press machine to melt / cure the prepreg by pressing and heating to bond the copper foil and the inner layer substrate. I can make it.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only preferred examples of the present invention, and the present invention is not limited by the following examples.

Example

Synthesis Example  1-denaturation Of polyamic acid (mPI01)  synthesis

Polyamic acid (m-PI01) having a maleic acid group introduced into at least one sock end of the main chain was synthesized.

10.01 g of ODA (Oxydianiline) and 70.85 g of NMP were sequentially added to a 1L round bottom jacket reactor and slowly stirred to completely dissolve. Then, 6FDA (4,4'-hexafluoro was maintained while maintaining the temperature of the reactor at 0 ° C. 18.88 g of isopropylidene) diphthalic anhydride) was slowly added and then dissolved with stirring. After the reaction mixture was stirred for 2 hours to fully react, 1.47 g of NDA (5-norbornene-2,3-dicarboxylic anhydride) was slowly added thereto, followed by further stirring at room temperature for 16 hours. Modified polyamic acid was obtained.

Wherein n is from 1 to 1,000.

Synthesis Example  2 denaturation Of polyic acid (mPI02)  synthesis

A maleic acid group was introduced into at least one sock end of the main chain to synthesize polyamic acid (m-PI02) to which liquid crystallinity was imparted.

9.61 g of BTFB (2,2'-Bis (trifluoromethyl) benzidine) and 51.1 g of NMP were sequentially added to a 1 L round bottom jacket reactor and slowly stirred to completely dissolve. PMDA was maintained at 0 ° C. while maintaining the temperature of the reactor at 0 ° C. 2.78 g (pyromellitic dianhydride) and 3.75 g of BPDA (4,4'-Biphthalic anhydride) were slowly added and dissolved with stirring. After the mixed solution was stirred for 2 hours to fully react, 0.88 g of maleic anhydride was slowly added thereto, and further stirred at room temperature for 16 hours to obtain a modified polyamic acid of the following Chemical Formula 10 in solution.

Wherein m and n are from 1 to 1,000.

Synthesis Example  3- Liquid crystal  Preparation of Polymer

In a 500 ml flask equipped with a condenser and a mechanical stirrer, 8.3 g (0.05 mol) of isophthalic acid, 18.8 g (0.1 mol) of 6-hydroxy-2-naphthoic acid, 5.5 g (0.05 mol) of 4-aminophenol, 32.7 g (0.32 mol) of acetic anhydride was added, and the temperature was gradually increased to 150 ° C. under a nitrogen atmosphere, followed by reaction for 4 hours while maintaining the temperature to complete the acetylation reaction. Subsequently, while removing acetic acid and unreacted acetic anhydride, the temperature was raised to 300 ° C. and reacted for 1 hour to prepare a liquid crystalline polyamide ester polymer.

Synthesis Example  4-liquid crystal Thermoset Oligomer  synthesis

100 ml of dimethylformamide was added to a 250 ml flask, and then dissolved by adding 3.274 g (0.03 mol) of 4-aminophenol, 4.655 g (0.025 mol) of 4,4-dihydroxybiphenyl, and 18 ml of triethylamine. 10.151 g (0.05 mol) of isophthaloyl chloride was added while cooling in ice water. After reacting at room temperature for 60 hours, the mixture was purified using water and ethanol and dried.

After dissolving 1 g of the dried sample in 9 g of NMP, 4-maleimido-benzoyl chloride, 0.1 g, and 10 ml of triethylamine were added thereto, and reacted at room temperature for 12 hours. A maleimide reactor was introduced at both terminals to introduce a liquid crystal thermoset of Chemical Formula 8. Three oligomers were obtained.

Example  One

A mixed solution was prepared by adding 2 g of a liquid crystalline polymer (poly amide-ester) obtained in Synthesis Example 3 and 0.5 g of a polyamic acid introduced with a terminal crosslinking functional group synthesized in Synthesis Example 1 to 9.5 g of NMP. Subsequently, the glass fiber was impregnated with 40 × 40 × 0.05 (mm) size and the specimen was placed on the electrolytic copper foil and cured at 300 ° C. at room temperature in a high temperature furnace for 2 hours. The prepared specimens were treated with 500 parts by weight of 500 ml of nitric acid solution to remove copper foil to obtain a prepreg.

For the obtained prepreg, the glass transition temperature (Tg) and the coefficient of thermal expansion (CTE) were calculated using a thermal analyzer (TMA: Thermomehcanical Analyzer, TA Instruments, TMA 2940) and are shown in Table 1 below.

Example  2

To 10.58 g of NMP, 2 g of a liquid crystalline polymer (poly amide-ester) obtained in Synthesis Example 3 and 0.85 g of a polyamic acid having a terminal crosslinking functional group synthesized in Synthesis Example 2 were added thereto to prepare a mixed solution. Subsequently, the glass fiber was impregnated with a size of about 40x40x0.05 (mm), and the specimen was placed on the electrolytic copper foil and cured at 300 ° C at room temperature in a high temperature furnace for 2 hours. The prepared specimen was treated with 50 parts by weight of nitric acid solution to remove copper foil to obtain a prepreg. The glass transition temperature (Tg) and the coefficient of thermal expansion (CTE) of the prepreg obtained in the same manner as in Example 1 were calculated and shown in Table 1 together.

Example  3

2 g of the liquid crystal thermoset obtained in Synthesis Example 4 and 0.5 g of the polyamic acid to which the terminal crosslinking functional group synthesized in Synthesis Example 1 was introduced were added to 9.5 g of NMP to prepare a mixed solution. Subsequently, the glass fiber was impregnated with 40 × 40 × 0.05 (mm) size and the specimen was placed on the electrolytic copper foil and cured at 300 ° C. at room temperature in a high temperature furnace for 2 hours. The prepared specimen was treated with 50 parts by weight of nitric acid solution to remove copper foil to obtain a prepreg. The glass transition temperature (Tg) and the coefficient of thermal expansion (CTE) of the prepreg obtained in the same manner as in Example 1 were calculated and shown in Table 1 together.

Example  4

The prepreg was prepared in the same manner as in Example 3, except that 2 g of the liquid crystal thermoset obtained in Synthesis Example 4 and 0.85 g of the polyamic acid having the terminal crosslinked functional group synthesized in Synthesis Example 2 were used in 10.58 g of NMP. prepreg) was prepared, and the glass transition temperature (Tg) and thermal expansion coefficient (CTE) of the prepreg thus obtained were calculated in the same manner as in Example 1, and the results are shown in Table 1 together.

Comparative example  One

       1 g of the liquid crystalline polymer obtained in Synthesis Example 3 was dissolved in 4 g of NMP at 120 ° C. for about 1 hour to prepare a solution. Subsequently, the glass fiber was impregnated with 40 × 40 × 0.05 (mm) size and the specimen was placed on the electrolytic copper foil and cured at 300 ° C. at room temperature in a high temperature furnace for 2 hours. The prepared specimens were treated with 500 parts by weight of 500 ml of nitric acid solution to remove copper foil to obtain a prepreg.

For the obtained prepreg, the glass transition temperature (Tg) and the coefficient of thermal expansion (CTE) were calculated in the range of 50 to 150 degrees using a thermal analyzer (TMA: Thermomehcanical Analyzer, TA Instruments, TMA 2940), and are shown in Table 1 below. It was.

Comparative example  2

The measurement was carried out in the same manner as in Comparative Example 1 except that the measurement temperature of the glass transition temperature and the thermal expansion coefficient of the sample was set to 150 to 250 degrees.

mPI101: modified polyamic acid prepared in Synthesis Example 1

mPI102: modified polyamic acid prepared in Synthesis Example 2

LCP: Liquid Crystalline Polymer Prepared in Synthesis Example 3

LCT: liquid crystal thermoset oligomer prepared in Synthesis Example 4

Through the results of Table 1, the composition for forming a printed circuit board according to one embodiment of the present invention (Example 1-4) has a glass transition temperature of 200 degrees or more, suitable for the substrate material, the coefficient of thermal expansion (CTE) of the base resin It can be seen that can provide a physical property of 20 ppm / ℃ or less. In contrast, in the case of the composition of Comparative Example 1-2 using only the liquid crystalline polymer, the CTE condition was satisfied, but the glass transition temperature was less than 200 degrees.

Although the present invention has been described in detail with reference to preferred embodiments of the present invention, it will be apparent to those skilled in the art that the present invention may be variously changed or modified without departing from the spirit and scope of the present invention. Modifications and variations are also to be construed as being included in the scope of protection of the present invention.

Claims (14)

A composition for forming a printed circuit board comprising a polyamic acid, a liquid crystalline polymer or a liquid crystal thermoset oligomer represented by the following Chemical Formula 1, wherein a crosslinking functional group is introduced into at least one of the sock ends of a main chain. [Formula 1]

Wherein A is represented by the following formula (2), when n is 2 or more, each A is the same as or different from each other, Each of Z ₁ and Z ₂ is the same as or different from each other, and is a monovalent crosslinking functional group having a carbon-carbon double bond, Y ₁ is a divalent aliphatic or aromatic organic group, n is an integer of 1 or more and 1,000 or less; [Formula 2]

Wherein X is a tetravalent aliphatic or aromatic organic group, Y ₂ is a divalent aliphatic or aromatic organic group, and Y ₁ and Y ₂ may be the same or different. The composition of claim 1, wherein the polyamic acid has a number average molecular weight of 1,000 to 90,000. The composition of claim 1, wherein the mixing ratio of the polyamic acid to the liquid crystalline polymer or the liquid crystal thermoset monomer is 1: 9 to 9: 1. In Formula 1 of claim 1, X is

A tetravalent organic group selected from the group consisting of; Each of Y ₁ and Y ₂ is the same as or different from each other;

A divalent organic group selected from the group consisting of Z ₁ and Z ₂ are each independently

Monovalent organic group selected from the group consisting of. According to claim 1, wherein the polyamic acid is a composition for forming a printed circuit board, characterized in that represented by the formula (3) or (4). [Formula 3]

Wherein k is 1 to 1,000, [Formula 4]

Wherein l is 1 to 500 and m is 1 to 900. The liquid crystal polymer of claim 1, wherein the liquid crystalline polymer is at least one selected from the group consisting of liquid crystalline polyester, liquid crystalline polyamide, liquid crystalline polyester amide, liquid crystalline polyester imide, and liquid crystalline polyamide imide. A composition for forming a printed circuit board. According to claim 1, wherein the liquid crystal thermoset oligomer is a composition for forming a printed circuit board, characterized in that represented by the formula [Formula 5]

Where Each Y ₃ , Y ₄ and Y ₅ is the same or different from each other and is a divalent aliphatic or aromatic organic group comprising at least one structure selected from the group consisting of esters, amides, ethers and imides, Ar comprises at least one aromatic structural unit selected from the group represented by the following formula (6), and each aromatic ring is directly connected or connected through at least one structure selected from the group consisting of esters, amides, ethers, and imides Is a divalent aromatic organic group, Each of Z ₃ and Z ₄ is the same as or different from each other, a monovalent organic group having a double bond or a triple bond, n is an integer of 1 or more and 10,000 or less. [Formula 6]

The composition of claim 1, wherein the composition further comprises an inorganic filler. The method of claim 8, wherein the inorganic filler is silica, aluminum borate, potassium titanate, magnesium sulfate, silicon carbide, zinc oxide, silicon nitride, silicon dioxide, aluminum titanate, barium titanate, barium strontium titanate and aluminum oxide Printed circuit board forming composition, characterized in that at least one selected from the group consisting of. The composition of claim 1, wherein the composition for forming a printed circuit board comprises 5 parts by weight to 100 parts by weight of polyamic acid and 5 to 100 parts by weight of a liquid crystalline polymer or a liquid crystal thermoset monomer based on 100 parts by weight of an organic solvent. Composition for forming a printed circuit board. A film prepared by solvent casting the composition for forming a printed circuit board according to any one of claims 1 to 10.  A prepreg prepared by impregnating a reinforcing material with a composition for forming a printed circuit board according to any one of claims 1 to 10.  13. The prepreg of claim 12, wherein the reinforcing material is selected from the group consisting of woven glass fibers, woven alumina glass fibers, glass fiber nonwovens, cellulose nonwovens, woven carbon fibers, and polymeric fabrics. A printed circuit board comprising the prepreg of claim 12.