CN106032406B - polymer, insulating film and flexible copper foil substrate - Google Patents

Abstract

The invention provides a polymer, an insulating film and a flexible copper foil substrate. The polymer includes at least 25 mol% of a repeating unit represented by formula 1:

Description

Polymer, insulating film and flexible copper foil substrate

technical field

The present invention relates to a polymer, an insulating film and a flexible copper foil substrate, and in particular to a polymer with low dielectric constant and low dielectric loss, an insulating film comprising the polymer, and a polymer comprising the Flexible copper foil substrate with insulating film.

Background technique

With the gradual development of electronic products towards thinner and lighter, the demand for flexible circuit boards has also increased significantly. The main upstream material of flexible circuit board is flexible copper foil substrate, which is usually made by coating or laminating polyimide polymer on copper foil. The polyimide polymer currently used in the industry has good heat resistance and dimensional stability, but its dielectric properties are poor, which limits its application range. Therefore, how to reduce the dielectric constant of the polyimide polymer so that it has good dielectric properties, thermal stability and dimensional stability is an extremely desirable goal in this field.

Contents of the invention

The invention provides a polymer, an insulating film and a flexible copper foil substrate.

The present invention provides a polymer comprising a novel imide repeating unit and an insulating film comprising the polymer has low dielectric constant and low dielectric loss, and the insulating film is suitable for flexible copper foil substrate.

The polymers of the present invention comprise at least 25 mol% of repeating units represented by formula 1:

wherein Ar is a tetravalent organic group derived from a tetracarboxylic dianhydride containing an aromatic group, and A is a divalent organic group derived from a diamine containing a cyclohexane group, and the carbon number of the divalent organic group is 8 to 18.

In one embodiment of the present invention, the number of repeating units represented by the above formula 1 is between 10 and 2000.

In one embodiment of the present invention, the above-mentioned Ar includes and At least one of, and B includes a single bond, -O-, -CH2-, -C(CH3)2-, -SO2- or -CO-.

In one embodiment of the present invention, the above-mentioned A includes and at least one of the

Polymers of the present invention include structures represented by Formula 2:

Where Ar is a tetravalent organic group derived from a tetracarboxylic dianhydride containing an aromatic group, A is a divalent organic group derived from a diamine containing a cyclohexane group, and the carbon number of the divalent organic group is from 8 to 18. Ψ is other repeating units and 0.25≤X≤1.

In one embodiment of the present invention, the above-mentioned Ar includes and At least one of, and B includes a single bond, -O-, -CH2-, -C(CH3)2-, -SO2- or -CO-.

In one embodiment of the present invention, the above-mentioned A includes and at least one of the

In one embodiment of the present invention, the above-mentioned Ψ is represented by formula 3:

Where Φ is a divalent organic group derived from a diamine containing an aromatic group or a cycloaliphatic group, Ar includes and At least one of, and B includes a single bond, -O-, -CH2-, -C(CH3)2-, -SO2- or -CO-.

In one embodiment of the present invention, the above Φ includes and at least one of the

In one embodiment of the present invention, the above Φ includes and and and The molar ratio is 9:1 to 1:9.

The insulating film of the present invention includes the aforementioned polymers.

In one embodiment of the present invention, the dielectric constant of the insulating film is 2.8 to 3.5, and the dielectric loss is 0.005 to 0.014.

The flexible copper foil substrate of the present invention includes copper foil and the aforementioned insulating film. The insulating film is arranged on the copper foil.

In one embodiment of the present invention, the flexible copper foil substrate further includes an adhesive layer disposed between the copper foil and the insulating film.

Based on the above, the polymer proposed by the present invention is manufactured by using a diamine monomer with a specific structure and a specific ratio and a dianhydride monomer containing an aromatic group, so that the polymer and the insulating film including it can have low dielectric properties at the same time. Electrical constant, low dielectric loss and high thermal stability.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, specific embodiments are described below in detail.

Detailed ways

Herein, a range indicated by "one value to another value" is a general representation to avoid enumerating all values in the range in the specification. Therefore, the description of a specific numerical range covers any numerical value in the numerical range and the smaller numerical range bounded by any numerical value in the numerical range, as if the arbitrary numerical value and the smaller numerical value are expressly written in the specification. same range.

Herein, the structure of a polymer or a group is sometimes represented by a skeleton formula. This notation can omit carbon atoms, hydrogen atoms, and carbon-hydrogen bonds. Of course, where atoms or atomic groups are explicitly shown in the structural formulas, the shown ones shall prevail.

One embodiment of the present invention provides a polymer comprising at least 25 mol% of repeating units represented by formula 1:

In the above formula 1, Ar is a tetravalent organic group derived from an aromatic group-containing tetracarboxylic dianhydride. That is, Ar is a residue other than two carboxylic anhydride groups (—(CO) ₂ O) in the aromatic group-containing tetracarboxylic dianhydride. Herein, the aromatic group-containing tetracarboxylic dianhydride is also referred to as a dianhydride monomer. In addition, in this embodiment, when preparing the repeating unit represented by Formula 1, one kind of dianhydride monomer or multiple kinds of dianhydride monomers can be used.

Specifically, Ar includes and and B includes a single bond, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ - or -CO-. That is to say, the tetracarboxylic dianhydride containing aromatic group is, for example, pyromellitic dianhydride (1,2,4,5-Benzenetetracarboxylic anhydride, PMDA for short), 3,3',4,4'- Biphenyltetracarboxylic dianhydride (3,3',4,4'-Biphenyltetracarboxylic dianhydride, BPDA for short), 4,4'-oxydiphthalic anhydride (Bis-(3-phthalyl anhydride)ether, ODPA for short ), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (3,3',4,4'-Benzophenonetetracarboxylic dianhydride, BTDA for short).

When the repeating unit represented by Formula 1 contains a tetravalent organic group derived from an aromatic group-containing tetracarboxylic dianhydride, high thermal stability can be imparted to the polymer. In addition, because the price of the tetracarboxylic dianhydrides containing aromatic groups listed above is cheap, so by using these tetracarboxylic dianhydrides containing aromatic groups, not only the polymer can have the properties that meet the market demand, but its manufacturing cost It can also be reduced, making it of industrial value.

In the above formula 1, A is a divalent organic group derived from a diamine containing a cyclohexane group, and the carbon number of the divalent organic group is 8-18, preferably 8-16. That is, A is a residue other than two amino groups (—NH ₂ ) in the cyclohexane group-containing diamine. Herein, the diamine containing a cyclohexane group is also referred to as a diamine monomer. In addition, in this embodiment, when preparing the repeating unit represented by Formula 1, one type of diamine monomer or multiple types of diamine monomers may be used.

Specifically, A includes and at least one of the That is to say, the diamine containing a cyclohexane group is, for example, 4,4'-diaminodicyclohexyl methane (4,4'-Diaminodicyclohexyl methane, MBCHA for short), 1,3-bis(aminomethyl) Cyclohexane (1,3-Di(aminomethyl)cyclohexane), 1,4-bis(aminomethyl)cyclohexane (1,4-Di(aminomethyl)cyclohexane), bis(aminomethyl)bicyclo[2.2. 1] Heptane (bis(aminomethyl)bicyclo[2.2.1]heptane), diaminomethylcyclohexylmethane (4,4'-Methylenebis(2-methylcyclohexylamine)).

It is worth mentioning that since 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(ammonia Methyl)bicyclo[2.2.1]heptane or diaminomethylcyclohexylmethane has the properties of low dielectric constant, low dielectric loss and good thermal stability, and the polymer is derived from 4,4'-di Aminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)bicyclo[2.2.1]heptane and di The repeating unit represented by formula 1 of at least one divalent organic group in aminomethylcyclohexylmethane can not only obtain high thermal stability, but also control its dielectric constant and dielectric loss. In detail, the structure does not contain the derivatives derived from 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane , bis(aminomethyl)bicyclo[2.2.1]heptane and diaminomethylcyclohexylmethane polymers with divalent organic groups, the structure contains 4,4'-diaminodicyclohexylmethane , 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)bicyclo[2.2.1]heptane and diaminomethylcyclohexyl The polymer of at least one divalent organic group in methane has a relatively low dielectric constant and dielectric loss.

In addition, as described above, the repeating unit represented by Formula 1 is an imide repeating unit obtained by imidating a dianhydride monomer and a diamine monomer. In detail, the imidization reaction is carried out in a solvent, such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (N,N-dimethylacetamide, DMAc), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), hexamethylphosphoramide or m-cresol. In addition, the imidization rate of the said imidation reaction was 100%.

In addition, in this embodiment, the number of repeating units represented by formula 1 is between 10 and 2000, preferably between 20 and 1500.

Another embodiment of the present invention provides a polymer comprising a structure represented by Formula 2:

In the above formula 2, the definition of Ar is the same as that of Ar in formula 1, and the definition of A is the same as that of A in formula 1. From another point of view, the structure represented by Formula 2 contains the repeating unit represented by Formula 1.

In the above formula 2, Ψ is another repeating unit. That is, Ψ is a repeating unit other than the repeating unit represented by Formula 1. In detail, Ψ may be a repeating unit represented by Formula 3:

In the above formula 3, the definition of Ar is the same as that of Ar in formula 1.

In the above formula 3, Φ is a divalent organic group derived from diamine containing an aromatic group or a cycloaliphatic group. That is, Φ is a divalent organic group derived from a diamine not containing a cyclohexane group. In addition, in this embodiment, when preparing other repeating units represented by formula 3, one kind of diamine monomer or multiple kinds of diamine monomers can be used.

Specifically, Φ includes and at least one of the That is to say, the diamines containing aromatic groups or cyclic aliphatic groups are, for example, p-phenylenediamine (p-Phenylenediamine, PDA for short), 4,4'-diaminobenzoanilide (4,4' -Diaminobenzanilide, referred to as DABA).

It is worth noting that the other repeating units represented by formula 3 contain divalent organic groups derived from p-phenylenediamine and/or 4,4'-diaminobenzoanilide, so that the intermolecular force is enhanced. In detail, p-phenylenediamine has a π electron system and has good symmetry, and by containing a divalent organic group derived from p-phenylenediamine, the π-π stacking force between molecules can be enhanced. , thus forming a π-π stacking (π-πstacking) structure; and 4,4'-diaminobenzanilide has an amide group belonging to a hydrogen-bonding group, so that when other repeating units shown in formula 3 contain derived from 4 , When the divalent organic group of 4'-diaminobenzanilide can form a hydrogen bond between molecules.

In the above formula 2, 0.25≤X≤1, preferably 0.5≤X≤1. That is to say, the structure shown in Formula 2 may only contain the repeating unit represented by Formula 1 without other repeating units, or contain other repeating units in a specific ratio. From another point of view, in this embodiment, when preparing the structure represented by Formula 2, one type of diamine monomer or multiple types of diamine monomers may be used.

Further, when X=1, the structure shown in Formula 2 only contains the repeating unit represented by Formula 1 and does not contain other repeating units. And when the polymer only includes the structure shown in Formula 2, it is obtained by using diamines containing cyclohexane (ie 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl) At least one of cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)bicyclo[2.2.1]heptane and diaminomethylcyclohexylmethane) as diamine mono body to prepare the polyimide polymer.

It is worth noting that, as mentioned above, 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, Bis(aminomethyl)bicyclo[2.2.1]heptane or diaminomethylcyclohexylmethane has the properties of low dielectric constant, low dielectric loss and good thermal stability, and tetracarboxylic dicarboxylic acid containing aromatic group Anhydrides have high thermal stability, so the polymer including the structure shown in Formula 2 not only has high thermal stability, but also has low dielectric constant and dielectric loss.

In addition, as mentioned above, the polyimide polymer is prepared in the presence of a solvent, such as NMP, DMAc, DMSO, DMF, hexamethylphosphoramide or m-cresol, and the polyimide The imidization ratio of the imide polymer was 100%.

And when 0.25≤X<1, the structure shown in Formula 2 contains other repeating units greater than 0 and less than or equal to 75 mole percent. Further, when the polymer only includes the structure shown in formula 2 and other repeating units are represented by formula 3, in addition to the diamine containing cyclohexane group, the polymer also adopts other diamines that do not contain cyclohexane Polyimide polymers prepared from diamine-based monomers.

Specifically, in one embodiment, the structure shown in Formula 2 can be prepared by using 4,4'-diaminodicyclohexylmethane and p-phenylenediamine as diamine monomers; in another embodiment, The structure shown in formula 2 can also be prepared by using 4,4'-diaminodicyclohexylmethane and 4,4'-diaminobenzoanilide as diamine monomers; or in another embodiment, the formula The structure shown in 2 can also be prepared by using 4,4'-diaminodicyclohexylmethane, p-phenylenediamine and 4,4'-diaminobenzoanilide as diamine monomers. In addition, when 4,4'-diaminodicyclohexylmethane, p-phenylenediamine and 4,4'-diaminobenzoanilide are used as diamine monomers at the same time, p-phenylenediamine and 4,4'- The molar ratio of diaminobenzoanilide is, for example, 9:1 to 1:9, preferably 4:1 to 3:2. However, the present invention is not limited thereto, and those skilled in the art should understand based on the foregoing, as long as diamines containing cyclohexane groups and diamines containing aromatic groups or cycloaliphatic groups but not containing cyclohexane groups are used at the same time It is within the scope of the present invention to prepare the structure shown in Formula 2 as a diamine monomer.

It is worth noting that, as mentioned above, containing divalent organic groups derived from p-phenylenediamine in the structure can enhance the π-π stacking force between molecules, and containing divalent organic groups derived from 4,4'-diaminobenzene The divalent organic group of the anilide can make the intermolecular hydrogen bond, therefore, the polymer including the structure shown in formula 2 can be derived from p-phenylenediamine and/or 4,4'-diaminobenzoanilide A divalent organic group can reduce its coefficient of thermal expansion. In detail, compared with polymers that do not contain divalent organic groups derived from p-phenylenediamine and 4,4'-diaminobenzoanilide, including those shown in Formula 2 that contain divalent organic groups derived from p-phenylenediamine and And/or 4,4'-diaminobenzanilide polymers with a divalent organic group structure have a lower coefficient of thermal expansion.

That is to say, the polymer comprising the structure shown in formula 2 is derived from 4,4'-diaminodicyclohexylmethane, 1,3 - At least one of bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)bicyclo[2.2.1]heptane and diaminomethylcyclohexylmethane In addition to a kind of divalent organic group, it is further matched with a divalent organic group derived from p-phenylenediamine and/or 4,4'-diaminobenzoanilide that can enhance the intermolecular force, making it in the dielectric A good balance can be achieved among physical properties such as properties, thermal stability and dimensional stability. That is to say, the polymer including the structure shown in formula 2 can simultaneously have the properties of low dielectric constant, low dielectric loss, thermal expansion coefficient similar to that of copper foil, and high thermal stability.

In addition, the polymer of the present invention may be in the form of a film, powder, or solution. Hereinafter, the polymer in the form of a thin film will be described as an example.

Another embodiment of the present invention provides an insulating film including the aforementioned polymer. In detail, the dielectric constant of the insulating film is 2.8 to 3.5, and the dielectric loss is 0.005 to 0.014.

It is worth noting that, as mentioned above, since the polymer not only has low dielectric constant, low dielectric loss and high thermal stability, but also has a thermal expansion coefficient close to that of copper foil, the insulating film can also have low The dielectric constant, low dielectric loss and high thermal stability, and further have a thermal expansion coefficient similar to that of copper foil, so that the insulating film not only meets the needs of the industry and is suitable for flexible copper foil substrates, but also has industrial value .

Another embodiment of the present invention also provides a flexible copper clad laminate (FCCL for short), including copper foil and the aforementioned insulating film, wherein the insulating film serves as a flexible substrate in the flexible copper clad laminate. As the copper foil, any copper foil known to those skilled in the art for flexible copper foil substrates can be used, such as electrolytic copper foil or rolled copper foil, and the thickness is not particularly limited.

In addition, the flexible copper foil substrate of the present invention also includes an adhesive layer disposed between the copper foil and the insulating film, so as to enable the copper foil to adhere closely to the insulating film. The material of the adhesive layer is, for example, thermosetting resin.

It is worth noting that, as mentioned above, due to the low dielectric constant, low dielectric loss and high thermal stability of the insulating film, the flexible copper foil substrate can have good reliability and process yield. In detail, the insulating film has a low dielectric constant and low dielectric loss, thereby reducing the electrical interference between the lines in the flexible circuit board made of the flexible copper foil substrate, and helping to avoid the occurrence of parasitic capacitance and The resulting power load, and avoid signal delay or interference caused by increased power consumption. In addition, since the insulating film can further have a thermal expansion coefficient similar to that of the copper foil, it can effectively suppress the dimensional change of the insulating film caused by the high-temperature process when manufacturing the flexible copper foil substrate, thereby avoiding the occurrence of alignment shift and improving the flexibility. Dimensional stability of permanent copper foil substrate.

Hereinafter, the features of the present invention will be described more specifically with reference to Examples 1-12 and Comparative Example 1. Although the following Examples 1 to 12 are described, the materials used, their amounts and ratios, processing details, processing flow, and the like can be appropriately changed without departing from the scope of the present invention. Therefore, the present invention should not be limitedly interpreted by the Examples described below.

Information on the main materials and equipment used to prepare the insulating films of Examples 1 to 7 and Comparative Example 1 is as follows.

4,4'-Diaminodicyclohexylmethane: purchased from TCI Company.

p-Phenylenediamine: purchased from Dongshin Chemical Company.

4,4'-Diaminobenzanilide: purchased from TCI Company.

3,3',4,4'-Biphenyltetracarboxylic dianhydride: purchased from JFE Chemical Co., Ltd.

Pyromellitic dianhydride: purchased from JFE Company.

4,4'-Oxydiphthalic anhydride: purchased from JFE Company.

N-methyl-2-pyrrolidone: purchased from TEDIA Company.

Low Determination Force Tester: manufactured by Mitutoyo America Corporation, the equipment name is Litematic LV-50A.

Example 1

Weigh 0.1486mol (31.27g) of 4,4'-diaminodicyclohexylmethane (hereinafter referred to as MBCHA) in a water bath (room temperature) and dissolve it in 420g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) as a solvent )middle. 0.1486mol (43.73g) of 3,3',4,4'-biphenyltetracarboxylic dianhydride (hereinafter referred to as BPDA) was added under a water bath. Next, under a water bath , a polyamic acid solution with a solid content of 15% is obtained after reacting for 5-7 hours. Afterwards, after baking the polyamic acid solution at 150°C for 10 minutes, an imidization reaction (dehydration cyclization) was carried out under a nitrogen atmosphere at 350°C for 30 to 40 minutes to obtain the insulating film of Example 1 , wherein the imidization ratio is 100%, and the thickness is measured with a low force measuring instrument, and the thickness is about 12 μm to 22 μm.

Example 2

In a water bath (room temperature), 0.0438 mol (9.21 g) of MBCHA was weighed and dissolved in 425 g of NMP as solvent. 0.1753 mol (51.57 g) of BPDA was added under a water bath. Next, 0.1315 mol (14.21 g) of p-phenylenediamine (hereinafter referred to as PDA) was added to the aforementioned solution. Afterwards, a polyamic acid solution with a solid content of 15% was obtained after reacting for 5-7 hours. Next, after baking the polyamic acid solution at 150°C for 10 minutes, an imidization reaction was carried out under a nitrogen atmosphere at 350°C for 30 to 40 minutes to obtain the insulating film of Example 2, wherein the imide The ratio is 100%, and the thickness is measured with a low force measuring instrument, and the thickness is about 12 μm to 22 μm.

Example 3

The insulating film of Example 3 is manufactured according to the same manufacturing procedure as that of Example 2, the only difference is that in Example 2, the molar ratio of MBCHA, PDA and BPDA is 0.25:0.75:1, and in Example 3 Among them, the molar ratio of MBCHA, PDA and BPDA is 0.5:0.5:1. In addition, in Example 3, the solid content of the polyamic acid solution, the imidization ratio, and the thickness of the insulating film are shown in Table 1, respectively.

Example 4

The insulating film of embodiment 4 is manufactured according to the same manufacturing procedure as embodiment 2, and its difference is only: in embodiment 2, the molar ratio of MBCHA, PDA and BPDA is 0.25:0.75:1, and in embodiment 4 Among them, the molar ratio of MBCHA, PDA and BPDA is 0.75:0.25:1. In addition, in Example 4, the solid content of the polyamic acid solution, the imidization ratio, and the thickness of the insulating film are shown in Table 1, respectively.

Example 5

In a water bath (room temperature), 0.074 mol (15.56 g) of MBCHA and 0.074 mol (16.81 g) of 4,4'-diaminobenzoylaniline (hereinafter referred to as DABA) were weighed and dissolved in 425 g of NMP as a solvent. 0.148 mol (42.64 g) of BPDA was added under a water bath. Afterwards, under a water bath, a polyamic acid solution with a solid content of 15% is obtained after reacting for 5-7 hours. Next, after baking the polyamic acid solution at 150° C. for 10 minutes, an imidization reaction was carried out under a nitrogen atmosphere at 350° C. for 30 to 40 minutes to obtain the insulating film of Example 5, wherein the imide The ratio is 100%, and the thickness is measured with a low force measuring instrument, and the thickness is about 12 μm to 22 μm.

Example 6

The insulating film of Example 6 is manufactured according to the same manufacturing procedure as that of Example 5, the only difference is that in Example 5, the molar ratio of MBCHA, DABA and BPDA is 0.5:0.5:1, and in Example 6 Among them, the molar ratio of MBCHA, DABA and BPDA is 0.75:0.25:1. In addition, in Example 6, the solid content of the polyamic acid solution, the imidization ratio, and the thickness of the insulating film are shown in Table 1, respectively.

Example 7

In a water bath (room temperature), 0.0806 mol (16.95 g) of MBCHA, 0.0644 mol (6.97 g) of PDA and 0.0161 mol (3.66 g) of DABA were weighed and dissolved in 425 g of NMP as a solvent. 0.1611 mol (47.42 g) of BPDA was added under a water bath. Afterwards, under a water bath, a polyamic acid solution with a solid content of 15% is obtained after reacting for 5-7 hours. Next, after baking the polyamic acid solution at 150°C for 10 minutes, an imidization reaction was carried out under a nitrogen atmosphere at 350°C for 30 to 40 minutes to obtain the insulating film of Example 7, wherein the imide The ratio is 100%, and the thickness is measured with a low force measuring instrument, and the thickness is about 12 μm to 22 μm.

Example 8

The insulating film of Example 8 is manufactured according to the same manufacturing procedure as that of Example 7, the only difference is that in Example 7, the molar ratio of MBCHA, PDA, DABA and BPDA is 0.5:0.4:0.1:1, and In Example 8, the molar ratio of MBCHA, PDA, DABA and BPDA is 0.5:0.35:0.15:1. In addition, in Example 8, the solid content of the polyamic acid solution, the imidization ratio, and the thickness of the insulating film are shown in Table 1, respectively.

Example 9

The insulating film of Example 9 is manufactured according to the same manufacturing procedure as that of Example 7, the only difference is that in Example 7, the molar ratio of MBCHA, PDA, DABA and BPDA is 0.5:0.4:0.1:1, and In Example 9, the molar ratio of MBCHA, PDA, DABA and BPDA is 0.5:0.3:0.2:1. In addition, in Example 9, the solid content of the polyamic acid solution, the imidization ratio, and the thickness of the insulating film are shown in Table 1, respectively.

Example 10

In a water bath (room temperature), weigh 0.2334mol (50.90g) of pyromellitic dianhydride (hereinafter referred to as PMDA) to be dissolved in 200g of NMP as a solvent, and weigh 0.2334mol (49.10g) of MBCHA to be dissolved in 200 g of NMP as solvent. Next, the PMDA solution and the MBCHA solution were evenly mixed, and reacted in a water bath for 10-12 hours to obtain a polyamic acid solution with a solid content of 20%. Next, after baking the polyamic acid solution at 150°C for 10 minutes, an imidization reaction was carried out in a nitrogen atmosphere at 350°C for 30 to 40 minutes to obtain the insulating film of Example 10, wherein the imide The ratio is 100%, and the thickness is measured with a low force measuring instrument, and the thickness is about 12 μm to 22 μm.

Example 11

The insulating film of Example 11 is manufactured according to the same manufacturing procedure as that of Example 10, the only difference is that in Example 10, the dianhydride monomer used is PMDA, and in Example 11, the used The dianhydride monomer is 4,4'-oxydiphthalic anhydride (hereinafter referred to as ODPA). In addition, in Example 11, the solid content of the polyamic acid solution, the imidization ratio, and the thickness of the insulating film are shown in Table 1, respectively.

Example 12

In a water bath (room temperature), 0.1723 mol (36.25 g) of MBCHA and 0.0191 mol (4.35 g) of DABA were weighed and dissolved in 400 g of NMP as a solvent. Under a water bath, 0.1914 mol (59.40 g) of ODPA was added. Afterwards, under a water bath, a polyamic acid solution with a solid content of 20% is obtained after reacting for 5-7 hours. Next, after baking the polyamic acid solution at 150°C for 10 minutes, an imidization reaction was carried out under a nitrogen atmosphere at 350°C for 30 to 40 minutes to obtain the insulating film of Example 12, wherein the imide The ratio is 100%, and the thickness is measured with a low force measuring instrument, and the thickness is about 12 μm to 22 μm.

Comparative example 1

The insulating film of Comparative Example 1 was manufactured according to the same manufacturing procedure as that of Example 1, the only difference being that in Example 1, the diamine monomer used was MBCHA, while in Comparative Example 1, the used The diamine monomer is DABA. In addition, in Comparative Example 1, the solid content of the polyamic acid solution, the imidization ratio, and the thickness of the insulating film are shown in Table 1, respectively.

Afterwards, the dielectric constant, dielectric loss, coefficient of thermal expansion (CTE), glass transition temperature and thermal cracking temperature of the insulating films of Examples 1 to 10 and Comparative Example 1 were measured respectively. The foregoing assays are described below, and the results of the assays are shown in Table 2.

<Measurement of dielectric constant and dielectric loss>

First, the insulating films of Examples 1 to 10 and Comparative Example 1 were made into film materials with a length and width of 7 cm×10 cm. Next, these film materials were placed in an oven and baked at a temperature of 130° C. for 2 hours, and then placed in an atmospheric environment for five days. After that, use a dielectric constant measuring device (manufactured by Rohde & Schwarz (ROHDE & SCHWARZ), the equipment name is ZVB20V Vector Network Analyzer) to measure the dielectric constant and dielectric loss of these films, and the measurement frequency is 10GHz. In the industry, in the application of flexible copper foil substrates, the dielectric constant of the insulating film is less than 3.2, which meets the product requirements, and the lower the value, the better the dielectric properties; and the dielectric loss of the insulating film is less than 0.01, which meets the product requirements. The lower the value, the better the dielectric properties.

<Measurement of Coefficient of Thermal Expansion>

First, the insulating films of Examples 1 to 10 and Comparative Example 1 were made into film materials with a length and width of 2 mm×30 mm, respectively. Then, using a thermomechanical analyzer (manufactured by Seiko Instrument Inc., the device name is EXSTAR 6000), these membrane materials were tested under a nitrogen atmosphere and a heating rate of 10 °C/min. The temperature was raised from 30°C to 450°C, and the average value of the dimensional changes between 50°C and 200°C was calculated to obtain the coefficient of thermal expansion. In the industry, in the application of flexible copper foil substrates, a thermal expansion coefficient below 30ppm/°C can be regarded as similar to that of copper foil (17ppm/°C).

<Measurement of Glass Transition Temperature>

First, the insulating films of Examples 1 to 10 and Comparative Example 1 were made into film materials with a length and width of 5 mm×40 mm, respectively. Then, using a dynamic mechanical analyzer (manufactured by Seiko Instrument Inc., the device name is EXSTAR 6100), these films were removed from The temperature was raised from 30°C to 450°C, and the temperature measured when the change rate of loss tangent (tanδ) reached the maximum was taken as the glass transition temperature. Generally speaking, when an insulating film is applied to a flexible copper foil substrate, its solder resistance is tested through a solder test (Solder Test), and the test condition of the solder test is usually maintained at 300°C for 30 seconds. Therefore, in the application of flexible copper foil substrates, the glass transition temperature of the insulating film is preferably above 300° C., and the larger the value, the better the thermal stability of the insulating film.

<Measurement of thermal cracking temperature>

Firstly, 0.5 g to 0.8 g of the insulating films of Examples 1 to 10 and Comparative Example 1 were weighed to serve as test film materials. Next, using a thermogravimetric loss analyzer (manufactured by Seiko Instrument Inc., equipment named EXSTAR 6000), these films were tested under a nitrogen atmosphere and a heating rate of 10°C/min. The material is heated from 30°C to 600°C, and the temperature measured when the film material loses 5% weight is taken as the thermal cracking temperature. In the industry, in the application of flexible copper foil substrates, the thermal cracking temperature of the insulating film generally needs to reach at least 400°C, and the larger the value, the better the thermal stability of the insulating film.

Table 2

As can be seen from Table 2, compared with the insulating film of Comparative Example 1 that does not contain divalent organic groups derived from 4,4'-diaminodicyclohexylmethane, the insulating films of Examples 1 to 10 containing divalent organic groups derived from 4,4'-diaminodicyclohexylmethane The insulating films of divalent organic radicals of '-diaminodicyclohexylmethane all have low dielectric constant and dielectric loss. In addition, it can be seen from Table 2 that the glass transition temperature of the insulating films of Examples 1 to 10 is between 262°C and 352°C and the thermal cracking temperature is between 464°C and 495°C, which shows that Examples 1 to 10 The insulating film of Example 10 has good thermal stability.

In addition, as can be seen from Table 2, compared with the insulating film of Example 1, Examples 2 to 9 also contain divalent organic compounds derived from p-phenylenediamine and/or 4,4'-diaminobenzoanilide. The base insulating film has a relatively low coefficient of thermal expansion. Furthermore, it can be seen from Table 2 that the dielectric constant of the insulating films of Examples 7 to 9 is between 3.15 and 3.17, the dielectric loss is between 0.052 and 0.063, and the thermal expansion coefficient is between 28.8ppm/ °C to 31.5ppm/°C, the glass transition temperature is between 285°C and 296°C, and the thermal cracking temperature is between 477°C and 489°C, which shows that the insulating films of Examples 7 to 9 have low The properties of dielectric constant, low dielectric loss, thermal expansion coefficient similar to copper foil and high thermal stability.

In addition, it can be seen from Table 2 that compared with the insulating films of Example 2 and Example 3, the insulating films of Example 5 and Example 6 have lower coefficients of thermal expansion. This shows that the structure contains - The ability of the divalent organic group of diaminobenzoaniline to regulate the coefficient of thermal expansion is better than that of the divalent organic group derived from p-phenylenediamine in the structure.

In addition, although the aforementioned properties were not measured for the insulating films of Examples 11 to 12, according to the measurement results of the insulating films of Examples 1 to 10 and Comparative Example 1, those skilled in the art should understand that Examples 11 to 12 The insulating film of Example 12 also has good dielectric properties, and compared to the insulating film of Example 11, the polyimide film of Example 12 has a lower coefficient of thermal expansion.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (9)

1. A polymer, characterized in that, comprises a structure represented by formula 2: in Ar is a tetravalent organic group derived from a tetracarboxylic dianhydride containing an aromatic group; A is a divalent organic group derived from a diamine containing a cyclohexane group, and the carbon number of the divalent organic group is 8 to 18; Ψ is represented by Equation 3: in Φ includes as well as 0.25≤X<1. 2. The polymer of claim 1, wherein Ar comprises and and B includes a single bond, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ - or -CO-. 3. The polymer of claim 1, wherein A comprises and at least one of the 4. The polymer of claim 1, wherein Φ comprises and and and The molar ratio is 9:1 to 1:9. 5. An insulating film comprising the polymer according to claim 1. 6. The insulating film according to claim 5, wherein a dielectric constant of the insulating film is 2.8 to 3.5. 7. The insulating film according to claim 5, wherein the dielectric loss of the insulating film is 0.005 to 0.014. 8. A flexible copper foil substrate, characterized in that it comprises: a copper foil; and An insulating film disposed on the copper foil, wherein the insulating film is the insulating film according to claim 5 . 9. The flexible copper foil substrate according to claim 8, further comprising an adhesive layer disposed between the copper foil and the insulating film.