CN111253744A

CN111253744A - Polyimide film and preparation method and application thereof

Info

Publication number: CN111253744A
Application number: CN202010058243.6A
Authority: CN
Inventors: 李义涛; 程堂剑; 云晧; 邓永茂; 陈志钊; 林丽平; 杨刚; 张凌飞
Original assignee: Dongguan HEC Tech R&D Co Ltd
Current assignee: Dongguan HEC Tech R&D Co Ltd
Priority date: 2020-01-18
Filing date: 2020-01-18
Publication date: 2020-06-09
Anticipated expiration: 2040-01-18
Also published as: CN111253744B

Abstract

The invention provides a polyimide film and a preparation method and application thereof. The polyimide film is obtained by performing polymerization reaction on a diamine monomer containing a cycloolefin structure and an aromatic dianhydride monomer and then imidizing. The diamine monomer containing the cycloolefin structure is weak in alkalinity, the prepared polyimide is high in molecular weight, and double bonds in the cycloolefin structure are easy to crosslink in the high-temperature imidization process, so that the heat resistance of the polyimide film is greatly improved. In the polyimide film provided by the invention, cyclic hydrocarbon and benzene ring are not coplanar, the dielectric loss is obviously reduced, and fluororesin is not added in the film, so that the high-temperature adhesion between the film and a substrate is good, the tensile strength of the film is high, the problem that the dielectric property, the thermal property and the mechanical property of the traditional polyimide film cannot be considered at the same time is solved, and the preparation process is simple and is suitable for being used for copper-clad plates.

Description

Polyimide film and preparation method and application thereof

Technical Field

The invention relates to the field of polyimide films, in particular to a polyimide film and a preparation method and application thereof.

Background

The polyimide has excellent heat resistance, mechanical, electrical insulation and chemical resistance, is widely applied to manufacturing flexible copper clad laminates, and plays a role in mechanical support and insulation of electronic circuits. The dielectric constant of a typical polyimide film is about 3.0, and the dielectric loss tangent is about 0.020. With the rapid development of electronic equipment and the arrival of the 5G era in recent years, the frequency band of signals in the 5G era is higher than that in the 4G era, so that the signals have higher loss in the transmission process of a circuit board. Therefore, higher requirements are placed on the dielectric loss and heat resistance of polyimide in the period of 5G, and for example, when the signal frequency is higher than 10GHz, the dielectric loss tangent of the polyimide material is required to be less than 0.005.

The general methods for reducing the dielectric loss of polyimide mainly include: (1) doping polyimide resin with low dielectric loss fluorine-containing resin such as polytetrafluoroethylene, fluorinated ethylene propylene copolymer and the like; (2) the polyimide structure is introduced with substituent groups with low polarization capability and a non-coplanar structure, so that the polarization capability of dipoles in molecules is reduced, and the free volume of the molecules is improved, such as an alicyclic structure, a long carbon chain structure and the like.

Chinese patent CN 107429028A disperses fluorine-containing resin into polyamic acid solution, imidizes and prepares polyimide film with low dielectric loss. However, the polyimide film prepared by the method has poor compatibility of the fluorine-containing resin and the polyimide, the mechanical property of the film is poor, the high-temperature bonding property of the film is poor due to the addition of the fluorine-containing resin, and the copper clad laminate prepared by laminating the film and the copper foil has low peel strength.

Chinese patent CN 104974595 a reacts diamine monomer with long carbon chain with aromatic dianhydride monomer to prepare polyimide film with low dielectric loss. However, in this method, when a long-carbon-chain diamine monomer is polymerized with an aromatic dianhydride monomer, a salt or gel is formed due to the strong basicity (pKa of about 10 and pKa of about 5.0) of the long-carbon-chain diamine, and thus it is difficult to obtain a high-molecular-weight polyimide, and the polyimide has a flexible aliphatic chain structure, which leads to a decrease in heat resistance of the polyimide.

Chinese patent CN 105461921A prepares a low dielectric polyimide film by polymerization reaction of saturated alicyclic diamine monomer and aromatic dianhydride monomer, and simultaneously adds a cross-linking agent to improve the adhesive property and the heat resistance. However, the saturated alicyclic diamine adopted in the method also has the problems of low polyimide molecular weight and poor heat resistance after reaction due to strong alkalinity, and the introduced cross-linking agent has the problem of compatibility with polyimide, thereby influencing the mechanical properties of the polyimide film.

Disclosure of Invention

The invention aims to solve the problems existing in the prior art that: the fluororesin-added low dielectric loss polyimide has at least one of the problems of poor mechanical property, poor high-temperature adhesive property, complex process, low molecular weight, poor heat resistance and the like. Therefore, on one hand, the invention provides a polyimide film, on the other hand, the invention provides a preparation method of the polyimide film, and on the third hand, the invention provides a copper-clad plate.

The technical scheme adopted by the invention is as follows:

in one aspect, the present invention provides a polyimide film having a crosslinked structure of repeating units of:

wherein n is an integer of 0 to 5; ar is an aromatic tetracarboxylic dianhydride derivative structural unit.

In some embodiments, n is 0, 1, or 2, whereby the resulting polyimide structure is more rigid and performs better.

In some embodiments, the Ar is selected from one or more of the following structures:

in some embodiments, the polyimide film has a dielectric loss tangent (10GHz) of less than 0.007.

In other embodiments, the polyimide film has a dielectric loss tangent (10GHz) between 0.002 and 0.007.

In some embodiments, the polyimide film has a tensile strength of 170-.

In some embodiments, the polyimide film has a glass transition temperature of 300-.

In some embodiments, the polyimide film has a thermal decomposition temperature of 510-540 ℃.

In some embodiments, the polyimide film has a peel strength of 1.00 to 1.20N/mm.

The polyimide film provided by the invention has a cross-linking structure, has high molecular weight, does not contain other additive components, ensures that the heat resistance and the mechanical property of the film are better, and reduces the polarization capability of dipoles in molecules and improves the free volume effect of the molecules because an alicyclic structure and a benzene ring contained in the polyimide structure form a non-planar structure, thereby reducing the dielectric loss of the polyimide.

In another aspect, the present invention provides a method for preparing the polyimide film described above, comprising: and polymerizing a diamine monomer containing a cycloolefin structure and an aromatic dianhydride monomer to obtain polyamic acid, and then performing imidization treatment to obtain the polyimide film.

Wherein the diamine monomer containing a cycloolefin structure has a structure shown in a formula I:

wherein n is an integer of 0 to 5, preferably 0, 1 or 2, i.e. the carbon number of the cycloolefin is: 4. 5 or 6.

Compared with the long-carbon-chain diamine or the diamine containing the saturated alicyclic structure used in the prior art, the diamine containing the cycloolefin structure is weak in alkalinity, the amount of generated salt or gel is small when the diamine is polymerized with the aromatic dianhydride monomer, the prepared polyimide is high in molecular weight, and meanwhile, after the diamine containing the cycloolefin structure is polymerized, double bonds in the structure are easy to crosslink in a high-temperature imidization process, so that the heat resistance of the polyimide is greatly improved.

In some embodiments, the cyclic olefin structure-containing diamine monomer is selected from the group consisting of 4,4'- (cyclobutyl-3-ene-1, 2-diylbis) diphenylamine (formula II-1), 3' - (cyclobutyl-3-ene-1, 2-diylbis) diphenylamine (formula II-2), 2'- (cyclobutyl-3-ene-1, 2-diylbis) diphenylamine (formula II-3), 4' - (cyclopentyl-3-ene-1, 2-diylbis) diphenylamine (formula II-4), 3'- (cyclopentyl-3-ene-1, 2-diylbis) diphenylamine (formula II-5), 2' - (cyclopentyl-3-ene-1, 2-diylbis (formula II-6), 4' - (cyclohexyl-2-ene-1, 4-diylbis) diphenylamine (formula II-7), 3' - (cyclohexyl-2-ene-1, 4-diylbis) diphenylamine (formula II-8), 2' - (cyclohexyl-2-ene-1, 4-diylbis) diphenylamine (formula II-9).

The diamine monomer containing the cycloolefin structure has the following specific structure:

in the present invention, the dianhydride monomer is not particularly limited, and an aromatic dianhydride monomer is preferable in view of thermal stability. In some embodiments, the aromatic dianhydride monomer is selected from one or more of 4,4' -oxydiphthalic anhydride (ODPA), pyromellitic dianhydride (PMDA), 4,4' -terephthaloxy diphthalic anhydride (triphenodiether dianhydride, HQDPA), bisphenol a type dianhydride (BPADA), 3,3',4,4' -biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4' -benzophenonetetracarboxylic dianhydride (BTDA), hexafluoro dianhydride (6FDA), 2,3,3',4' -biphenyltetracarboxylic dianhydride, 3,4' -oxydiphthalic anhydride, 3,3',4,4' -diphenylsulfonetetracarboxylic dianhydride.

The polyamic acid described above can be prepared by methods known in the art. For example, the diphenylamine monomer containing a cycloolefin structure is fully dissolved in an organic solvent, then the aromatic dianhydride monomer is added, and the mixture is reacted for 2 to 24 hours, preferably for 12 hours at the temperature of 20 to 30 ℃ under the protection of nitrogen or other inert gases, so as to obtain the polyamic acid solution.

In some embodiments, the molar ratio of the diamine monomer containing a cyclic olefin structure to the aromatic dianhydride monomer is 0.9 to 1.1:1, preferably 1: 1; the total mass of the diamine monomer containing a cycloolefin structure and the aromatic dianhydride monomer is 8 to 35%, preferably 8 to 12% of the mass of the polyamic acid solution, for example: 8%, 9%, 10%, 11%, 12%.

In some embodiments, the organic solvent is one or more of N, N-dimethylformamide, N-dimethylacetamide, sulfolane, m-cresol, methyl sulfoxide, N-methylpyrrolidone, diphenyl sulfone, tetrahydrofuran, chloroform, acetone, γ -butyrolactone, methanol, cyclohexanone, methylcyclohexane.

In the above production method, the imidization treatment includes: keeping the temperature at 350-450 ℃ for 50-60 min. The polyamic acid contains a cycloolefin structure, has good chain segment flexibility, is easy to rotate, is easy to generate imine bonds, and has relatively low imidization temperature. In the present invention, the polyamic acid having a cycloolefin structure can be completely imidized at 250 ℃ and the temperature is raised to 350 ℃ or higher to cleave the double bond in the cycloolefin structure and form a crosslinked polyimide, thereby obtaining a polyimide film having more excellent heat resistance.

In the above preparation method, the imidization treatment specifically includes: drying at low temperature to remove the organic solvent, heating to 350-: heating to 350 deg.C, 400 deg.C or 450 deg.C, and keeping the temperature for 60min to imidize polyamic acid and obtain cross-linked polyimide. If the temperature is too low, the resulting polyimide is not crosslinked, resulting in deterioration of heat resistance and dielectric properties of the film.

In some embodiments, the imidization treatment comprises: drying at 40-80 deg.C for 6-20 h; then heating to 150 ℃, and preserving heat for 30-90 min; heating to 200 deg.C, and maintaining the temperature for 30-90 min; heating to 250 deg.C, and maintaining for 30-90 min; finally heating to 350-450 ℃, and preserving the heat for 50-60 min.

In a third aspect, the invention provides a copper-clad plate which comprises the polyimide film. The polyimide film of the present invention has low dielectric loss even in an environment with a high signal frequency (3GHz or higher), for example: when the film is applied to a copper-clad plate, the copper-clad plate can keep excellent performance under a high-frequency environment, and therefore, the film is particularly suitable for the high-frequency copper-clad plate.

The copper-clad plate can be prepared by coating the polyamic acid solution on a copper foil and then imidizing, or by laminating the polyimide film and the copper foil at high temperature.

The invention has the beneficial effects that:

the polyimide film provided by the invention is obtained by carrying out polymerization reaction on a diamine monomer containing a cycloolefin structure and an aromatic dianhydride monomer and then imidizing. The diamine monomer containing the cycloolefin structure is weak in alkalinity, the prepared polyimide is high in molecular weight, and double bonds in the cycloolefin structure are easy to crosslink in the high-temperature imidization process, so that the heat resistance of the polyimide film is greatly improved. In the polyimide film provided by the invention, cyclic hydrocarbon and benzene ring are not coplanar, the dielectric loss is obviously reduced, and fluororesin is not added in the film, so that the high-temperature adhesion between the film and a substrate is good, the tensile strength of the film is high, the problem that the dielectric property, the thermal property and the mechanical property of the traditional polyimide film cannot be considered at the same time is solved, and the preparation process is simple.

Definition of terms

In the present invention, when the name and structure of the compound conflict, the structure of the compound is taken as the standard.

All ranges cited herein are inclusive, unless expressly stated to the contrary.

The terms "a" or "an" are used herein to describe elements and components described herein. This is done merely for convenience and to provide a general sense of the scope of the invention. Such description should be understood to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. "plural" means two or more.

The numbers in this disclosure are approximate, regardless of whether the word "about" or "approximately" is used. The numerical value of the number may have differences of 1%, 2%, 5%, 7%, 8%, 10%, etc. Whenever a number with a value of N is disclosed, any number with a value of N +/-1%, N +/-2%, N +/-3%, N +/-5%, N +/-7%, N +/-8% or N +/-10% is explicitly disclosed, wherein "+/-" means plus or minus, and a range between N-10% and N + 10% is also disclosed.

The following definitions, as used herein, should be applied unless otherwise indicated. For the purposes of the present invention, the chemical elements are in accordance with the CAS version of the periodic Table of elements, and the 75 th version of the handbook of chemistry and Physics, 1994. In addition, general principles of Organic Chemistry can be found in the descriptions of "Organic Chemistry", Thomas Sorrell, University Science Books, Sausaltito: 1999, and "March's Advanced Organic Chemistry" by Michael B.Smith and JerryMarch, John Wiley & Sons, New York:2007, the entire contents of which are incorporated herein by reference.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can also be used in the practice or testing of embodiments of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety, unless a specific section is cited. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

Detailed Description

The following are only specific examples of the present invention and should not be construed as limiting the invention. Any simple variations, equivalent substitutions or modifications based on the present invention to achieve substantially the same technical effects are within the scope of the present invention.

The synthesis of the above diamine monomers of formulae II-1 to II-7 is similar, reference: J.chem.Soc.,1958,3298-3313, below, for example of formula II-1, the synthesis procedure is as follows:

1mol of potassium p-nitro (benzo) phenate and 0.5mol of 3, 4-dibromocyclobutene are mixed in 400mL of anhydrous carbon tetrachloride and 400mL of anhydrous acetone, heated to 50 ℃ for reflux for 6-8h, then filtered, and the filtrate is evaporated in vacuo. The residue was dissolved in ether, washed successively with water, dilute aqueous sodium hydroxide solution and water, and the ether solution was dried and evaporated to give 3, 4-bis (4-nitrophenoxy) cyclobut-1-ene which crystallized from petroleum ether.

0.5mol of 3, 4-bis (4-nitrophenoxy) cyclobut-1-ene are dissolved in 200mL of aqueous acetic acid (85%), reduced by adding 50g of iron, the suspension is boiled for 3min, filtered hot, cooled and slowly treated with 200mL of concentrated hydrochloric acid until the brown colour disappears and then cooled again. After 2h, the hydrochloride salt was filtered off and the filtrate was evaporated in vacuo and the residue was treated with a small amount of water to give more hydrochloride salt. The hydrochloride obtained is dissolved in a small amount of water, treated with concentrated hydrochloric acid, cooled and filtered, the hydrochloride is washed with acetone and dried. After washing with 200mL of an aqueous sodium hydroxide solution (1mol/L) and filtration, 4' - (cyclobutyl-3-ene-1, 2-diylbutoxy) diphenylamine (formula II-1) was obtained by crystallization from ethanol. The reaction formula is shown as the following formula:

example 1

(1) 13.4060g (0.050mol) of 4,4' - (cyclobutyl-3-ene-1, 2-diyl dioxy) diphenylamine (CBDA) monomer is added into a dry and clean 500mL three-necked bottle, 225g of N-methylpyrrolidone (NMP) is added to be completely dissolved, 10.9060g (0.050mol) of pyromellitic dianhydride (PMDA) is added, and reaction is carried out at 25 ℃ for 12 hours under the protection of nitrogen to obtain a polyamic acid solution;

(2) respectively coating the polyamic acid solution on a dry and clean copper foil and a glass sheet to form a film;

(3) drying the coated copper foil and the coated glass sheet at 80 ℃ for 6h in a nitrogen atmosphere; then heating to 150 ℃, and preserving heat for 1 h; heating to 200 deg.C, and maintaining for 1 h; heating to 250 deg.C, and maintaining for 1 h; finally heating to 350 ℃, preserving heat for 1h, and cooling to room temperature. The film coated on the glass plate was boiled with boiling water until the polyimide film was removed from the glass plate, to obtain a polyimide film having a thickness of 20 μm. The copper foil coated with the polyimide film was used in the test.

Example 2

(1) 14.1070g (0.050mol) of 4,4' - (cyclopentyl-3-ene-1, 2-diyl dioxy) diphenylamine (CPDA) monomer is added into a dry and clean 500mL three-necked bottle, 225g of N-methylpyrrolidone (NMP) is added to be completely dissolved, 10.9060g (0.050mol) of pyromellitic dianhydride (PMDA) is added, and reaction is carried out at 25 ℃ for 12 hours under the protection of nitrogen to obtain a polyamic acid solution;

Example 3

(1) 14.8075g (0.050mol) of 4,4' - (cyclohexyl-2-ene-1, 4-dihydroxy diphenylamine (CHDA) monomer is added into a dry and clean 500mL three-necked bottle, 225g of N-methylpyrrolidone (NMP) is added to be completely dissolved, 10.9060g (0.050mol) of pyromellitic dianhydride (PMDA) is added, and the mixture reacts for 12 hours at 25 ℃ under the protection of nitrogen to obtain a polyamic acid solution;

Example 4

(1) 7.4038g (0.025mol) of 4,4'- (cyclohexyl-2-alkene-1, 4-diyl dioxy) diphenylamine (CHDA) monomer and 7.0535g (0.025mol) of 4,4' - (cyclopentyl-3-alkene-1, 2-diyl dioxy) diphenylamine (CPDA) monomer are added into a dry and clean 500mL three-necked bottle, 225g of N-methylpyrrolidone (NMP) is added to be completely dissolved, 10.9060g (0.050mol) of pyromellitic dianhydride (PMDA) is added, and the mixture is reacted for 12 hours at 25 ℃ under the protection of nitrogen to obtain a polyamic acid solution;

Example 5

(3) drying the coated copper foil and the coated glass sheet at 80 ℃ for 6h in a nitrogen atmosphere; then heating to 150 ℃, and preserving heat for 1 h; heating to 200 deg.C, and maintaining for 1 h; heating to 250 deg.C, and maintaining for 1 h; finally heating to 400 ℃, preserving heat for 1h, and cooling to room temperature. The film coated on the glass plate was boiled with boiling water until the polyimide film was removed from the glass plate, to obtain a polyimide film having a thickness of 20 μm. The copper foil coated with the polyimide film was used in the test.

Example 6

(3) drying the coated copper foil and the coated glass sheet at 80 ℃ for 6h in a nitrogen atmosphere; then heating to 150 ℃, and preserving heat for 1 h; heating to 200 deg.C, and maintaining for 1 h; heating to 250 deg.C, and maintaining for 1 h; finally heating to 450 ℃, preserving heat for 1h, and cooling to room temperature. The film coated on the glass plate was boiled with boiling water until the polyimide film was removed from the glass plate, to obtain a polyimide film having a thickness of 20 μm. The copper foil coated with the polyimide film was used in the test.

Comparative example 1

(1) 10.0045g (0.050mol) of 4,4' -diaminodiphenyl ether (ODA, without a cyclic olefin structure) monomer is added into a dry and clean 500mL three-necked bottle, 225g of N-methylpyrrolidone (NMP) is added to be completely dissolved, 10.9060g (0.050mol) of pyromellitic dianhydride (PMDA) is added, and reaction is carried out for 12 hours at 25 ℃ under the protection of nitrogen to obtain a polyamic acid solution;

(3) drying the coated copper foil and the coated glass sheet at 80 ℃ for 6h in a nitrogen atmosphere; then heating to 150 ℃, and preserving heat for 1 h; heating to 200 deg.C, and maintaining for 1 h; heating to 250 deg.C, and maintaining for 1 h; finally, heating to 350 ℃, preserving heat for 1h, and cooling to room temperature. The film coated on the glass plate was boiled with boiling water until the polyimide film was removed from the glass plate to obtain a polyimide film having a thickness of 20 μm. The copper foil coated with the polyimide film was used in the test.

Comparative example 2

(1) 14.8075g (0.050mol) of 4,4' - (cyclohexyl-2-ene-1, 4-diylbis) diphenylamine (CHDA) monomer is added into a dry and clean 500mL three-necked bottle, 225g of N-methylpyrrolidone (NMP) is added to be completely dissolved, 10.9060g (0.050mol) of pyromellitic dianhydride (PMDA) is added, and reaction is carried out at 25 ℃ for 12 hours under the protection of nitrogen to obtain a polyamic acid solution;

(3) drying the coated copper foil and the coated glass sheet at 80 ℃ for 6h in a nitrogen atmosphere; then heating to 150 ℃, and preserving heat for 1 h; heating to 200 deg.C, and maintaining for 1 h; finally heating to 250 ℃, preserving heat for 1h, and cooling to room temperature. The film coated on the glass plate was boiled with boiling water until the polyimide film was removed from the glass plate, to obtain a polyimide film having a thickness of 20 μm. The copper foil coated with the polyimide film was used in the test.

Comparative example 3

(1) 10.0045g (0.050mol) of 4,4' -diaminodiphenyl ether (ODA) monomer is added into a dry and clean 500mL three-necked bottle, 225g of N-methylpyrrolidone (NMP) is added to be completely dissolved, 10.9060g (0.050mol) of pyromellitic dianhydride (PMDA) is added, and reaction is carried out for 12 hours at 25 ℃ under the protection of nitrogen to obtain polyamic acid solution;

(2) adding 14.0g of fluorine-containing resin Polytetrafluoroethylene (PTFE) into the polyamic acid solution, and uniformly stirring to obtain a fluororesin-filled polyamic acid solution;

(3) coating the polyamide acid solution filled with the fluororesin on a dry and clean copper foil and a glass sheet respectively to form a film;

(4) drying the coated base material at 80 ℃ for 6h in a nitrogen atmosphere; then heating to 150 ℃, and preserving heat for 1 h; heating to 200 deg.C, and maintaining for 1 h; heating to 250 deg.C, and maintaining for 1 h; finally, heating to 350 ℃, preserving heat for 1h, and cooling to room temperature. The film coated on the glass plate was boiled with boiling water until the polyimide film was removed from the glass plate to obtain a polyimide film having a thickness of 20 μm. The copper foil coated with the polyimide film was used in the test.

Test data

The polyimide films of examples 1 to 6 and comparative examples 1 to 3 were tested for mechanical properties, dielectric loss tangent and thermal properties, and adhesion between the films and copper foil was tested.

(1) Dielectric loss tangent: the dielectric loss tangent of each polyimide film was measured based on the IPC-TM-650 standard.

(2) Tensile strength: the tensile strength of each polyimide film was measured based on the GB/T13022 standard.

(3) Glass transition temperature: the glass transition temperature of each polyimide film was measured based on GB/T22567-2008 standard.

(4) Thermal decomposition temperature: the thermal decomposition temperature of each polyimide film was measured based on GB/T31850-.

(5) Peel strength: the peel strength of each polyimide film was measured based on the GB/T13557-2017 standard.

The test data are shown in table 1.

TABLE 1 polyimide film Properties

As is apparent from Table 1, the polyimide film of the present invention has a low dielectric loss tangent, a high tensile strength, a high heat resistance and a high peel strength from a copper foil. The polyimide film which was not crosslinked at a high temperature (comparative example 2) was significantly reduced in heat resistance. The adhesion and tensile strength of the fluororesin-filled polyimide film (comparative example 3) to the copper foil were significantly reduced.

Claims

1. A polyimide film, wherein the polyimide has a crosslinked structure of repeating units of:

2. The polyimide film according to claim 1, wherein n is an integer of 0 to 2.

3. The polyimide film of claim 1, wherein Ar is selected from one or more of the following structures:

4. the polyimide film as claimed in any one of claims 1 to 3, wherein the polyimide film has a dielectric loss tangent of less than 0.007 at 10GHz, a tensile strength of 170-190MPa, a glass transition temperature of 300-360 ℃, a thermal decomposition temperature of 510-540 ℃ and a peel strength of 1.00-1.20N/mm.

5. A method for producing the polyimide film according to any one of claims 1 to 4, comprising: and polymerizing a diamine monomer containing a cycloolefin structure and an aromatic dianhydride monomer to obtain polyamic acid, and then performing imidization treatment to obtain the polyimide film.

6. The method according to claim 5, wherein the diamine monomer having a cycloolefin structure has a structure represented by the formula I:

wherein n is an integer of 0 to 5.

7. The method according to claim 5 or 6, wherein the diamine monomer containing a cyclic olefin structure is selected from one or more of the following formulae:

8. the method according to claim 5, wherein the aromatic dianhydride monomer is selected from one or more of 4,4' -oxydiphthalic anhydride, pyromellitic dianhydride, 4,4' -terephthaloyl diphthalic anhydride, bisphenol A dianhydride, 3,3',4,4' -biphenyltetracarboxylic dianhydride, 3,3',4,4' -benzophenonetetracarboxylic dianhydride, hexafluoro dianhydride, 2,3,3',4' -biphenyltetracarboxylic dianhydride, 3,4' -oxydiphthalic anhydride, and 3,3',4,4' -diphenylsulfonetetracarboxylic dianhydride.

9. The production method according to claim 5, wherein the imidization treatment includes: keeping the temperature at 350-450 ℃ for 50-60 min.

10. A copper-clad plate characterized by comprising the polyimide film according to any one of claims 1 to 4.