CN111393646A

CN111393646A - Low-dielectric and low-loss polyimide composite material, and preparation method and application thereof

Info

Publication number: CN111393646A
Application number: CN202010367545.1A
Authority: CN
Inventors: 刘欢; 李智; 彭冲; 田琰; 林德宝; 宋锡滨
Original assignee: Shanghai Guoci New Material Technology Co ltd
Current assignee: Shanghai Guoci New Material Technology Co ltd
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2020-07-10

Abstract

The invention belongs to the technical field of organic polymer materials, and particularly relates to a low-dielectric and low-loss polyimide composite material suitable for 5G system application, and further discloses a preparation method and application thereof. According to the preparation method of the low-dielectric and low-loss polyimide composite material, disclosed by the invention, based on a hydrothermal synthesis mode, the mesoporous material is subjected to surface modification by using the aminosilane modifier, and the mesoporous material subjected to amino modification is introduced onto the polyimide, so that the dispersion uniformity of the mesoporous material and the polyimide precursor in blending and the film forming property of the material are effectively improved, the dielectric constant and the dielectric loss of the polyimide material are effectively reduced, and the dielectric property of the material is improved.

Description

Low-dielectric and low-loss polyimide composite material, and preparation method and application thereof

Technical Field

The invention belongs to the technical field of organic polymer materials, and particularly relates to a low-dielectric and low-loss polyimide composite material suitable for 5G system application, and further discloses a preparation method and application thereof.

Background

In recent years, with the development of 5G communication technology, an antenna is one of the fastest growing industries in the future, and a mobile phone antenna has been developed from an early external antenna to an internal antenna, and forms a market pattern with a flexible board as a mainstream process. With the development of the microelectronics industry, the functions of microelectronic elements are enhanced but the volume is reduced, and the size of super-large-scale integrated circuits is reduced, so that the resistance and capacitance (Rc) delay of metal interconnects is increased nearly to the square, and the signal transmission delay and crosstalk are caused to directly affect the performance of devices. In order to reduce the increase in power consumption due to signal propagation delay, crosstalk, and dielectric loss, to satisfy the demand for higher-speed signal transmission, and to further improve the function of electronic circuits, it is necessary to make the dielectric interlayer insulating material have a lower dielectric constant.

Polyimide is widely applied to the microelectronic industry due to excellent performance, however, the dielectric constant of general polyimide is about 3.0-3.6, and the polyimide can not meet the transmission requirement of 5G high frequency in the future. Meanwhile, due to higher requirements in the application field, in addition to the dielectric property, PI is also required to have excellent heat resistance, mechanical properties, chemical stability and solvent resistance. Therefore, the modification of the conventional polyimide substrate to effectively reduce the dielectric constant and dielectric loss is an important development trend in the future.

At present, the conventional method for reducing the dielectric constant of polyimide in the prior art mainly comprises the following steps:

(1) introduction of fluorine atoms or fluorine-containing groups having low electron polarizability: fluorine atoms or fluorine-containing groups are introduced into the molecular main chain of the polyimide, so that the polarization capability of the polyimide can be reduced, and the purpose of reducing the dielectric constant is achieved, but the synthesis process of the fluorine-containing polyimide is complex, and the mechanical property of the film is reduced, so that the application effect is influenced;

(2) introducing a low dielectric constant polymer block or aliphatic chain, but the improvement on lowering the dielectric constant of polyimide is very limited;

(3) introducing micropores into polyimide and preparing a polyimide porous material: the preparation of nano-hollow or mesoporous structures in the polyimide preparation process aims to introduce air (dielectric constant is about 1.0) into polyimide, which is an effective method for reducing the dielectric constant of polyimide, and the dielectric properties of materials can be regulated by regulating the porosity and the pore size, so that the preparation method has attracted much attention and is a hot spot of research in recent years.

For example, the low dielectric constant polyimide/mesoporous molecular sieve hybrid material disclosed in chinese patent CN101560299A improves the dielectric properties of polyimide films by doping selected mesoporous molecular sieve materials during the polyimide preparation process. However, the dielectric property of polyimide materials is not very good because of the problems of the influence of the properties of the selected mesoporous molecular sieve materials and the nonuniformity of the materials in the dispersion process.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to provide a low-dielectric and low-loss polyimide composite material suitable for 5G system application, so as to solve the problem that the properties such as dielectric constant of the polyimide material in the prior art are not suitable for the application in the 5G field;

the second technical problem to be solved by the present invention is to provide a preparation method and an application of the polyimide composite material with low dielectric constant and low loss.

In order to solve the technical problems, the method for preparing the polyimide composite material with low dielectric constant and low loss comprises the following steps:

(1) taking an aminosilane modifier, sequentially adding a mesoporous material, a reaction solvent acetonitrile and a dilute nitric acid solution, uniformly dispersing, and carrying out hydrothermal reaction at the temperature of 150-; after the reaction is finished, collecting the precipitate, washing, drying and roasting to obtain an amino mesoporous material with the surface modified by amino, and dispersing the amino mesoporous material in an organic solvent for later use;

(2) and under the protective atmosphere, adding the organic solvent containing the amino mesoporous material into a polar solvent, adding an organic acid anhydride monomer, fully and uniformly mixing, and reacting to obtain the polyimide composite material containing the amino mesoporous material and the polyimide precursor solution with low dielectric and low loss.

Specifically, in the step (1), the mesoporous material includes mesoporous KIT, FDU or MCM mesoporous material, and more preferably KIT-6.

Specifically, in the step (1), the aminosilane modifier includes phenylaminomethyltrimethylsilane and/or phenylaminomethyltriethylsilane, preferably phenylaminomethyltrimethylsilane.

Specifically, in the step (1), the acidic solution includes dilute nitric acid, and the mass concentration is preferably 10 to 20 wt%, and more preferably 15 wt%.

Specifically, in the step (1), the reaction solvent includes acetonitrile, dichloromethane, chloroform or toluene.

Specifically, in the step (1), the molar ratio of the aminosilane modifier to the mesoporous material to the acetonitrile to the dilute nitric acid solution is 0.1-0.3: 0.8-1.2: 0.3-0.7: 0.05 to 0.15, and preferably 0.2: 1: 0.5: 0.1.

specifically, in the step (1), ultrasonic dispersion treatment is adopted for 2-12h in the dispersion step.

Specifically, in the step (1), the temperature of the hydrothermal synthesis step is preferably 160-170 ℃, and the hydrothermal synthesis time is 24-48 h.

Specifically, in the step (1), the temperature of the roasting step is 200-.

Specifically, in the step (1), the washing step includes a step of washing with distilled water and ethanol in sequence.

Specifically, in the step (1), the drying step is preferably vacuum drying.

Specifically, the step (1) further comprises a step of sanding the obtained amino mesoporous material to a particle size of 500-2000nm, preferably 600-800 nm.

Specifically, in the step (1), the organic solvent comprises methanol, ethanol and/or propanol, preferably ethanol, and the dispersion concentration of the amino mesoporous material in the organic solvent is controlled to be 0.1-0.6 mol/L, and preferably 0.2-0.5 mol/L.

Specifically, in the step (2), the mass ratio of the organic acid anhydride monomer to the amino group-containing mesoporous material is 3-4: 1.

specifically, in the step (2), the organic acid anhydride monomer includes one or a mixture of more of pyromellitic dianhydride, monoether tetracarboxylic dianhydride, triphendiether tetracarboxylic dianhydride, biphenyl ether dianhydride, and benzophenone tetracarboxylic dianhydride; further preferably one or more of pyromellitic dianhydride, monoether tetracarboxylic dianhydride and triphendiether tetracarboxylic dianhydride;

the polar solvent comprises N, N-dimethylacetamide, N-dimethylformamide or N, N-dimethylpropionamide.

The polar solvent and the amount used are such that the reaction is sufficiently facilitated.

Specifically, in the step (2), the organic solvent containing the amino group mesoporous material is added into the polar solvent through a peristaltic pump, and the flow rate is preferably controlled to be 1-5ml/min, and more preferably 2-4 ml/min.

The invention also discloses a low-dielectric and low-loss polyimide film prepared from the low-dielectric and low-loss polyimide composite material by a conventional method.

Specifically, the conventional method includes a casting method.

According to the preparation method of the low-dielectric and low-loss polyimide composite material, disclosed by the invention, based on a hydrothermal synthesis mode, the mesoporous material is subjected to surface modification by using the aminosilane modifier, and the mesoporous material subjected to amino modification is introduced onto the polyimide, so that the dispersion uniformity of the mesoporous material and the polyimide precursor in blending and the film forming property of the material are effectively improved, the dielectric constant and the dielectric loss of the polyimide material are effectively reduced, and the dielectric property of the material is improved.

According to the low-dielectric and low-loss polyimide composite material, the inorganic filler with a mesoporous structure is added into the polyamic acid resin, so that the dielectric constant and the low dielectric loss of the polyimide film are effectively reduced, the dielectric constant of the obtained polyimide material is less than 2.5, the dielectric loss is less than 0.0005, and the polyimide composite material is more suitable for the application in the 5G field; meanwhile, the high mechanical property and the heat resistance of the antenna are improved, the requirements in the field of 5G antennas can be met, and the antenna is simple in method, low in cost, short in period and simple and convenient in operation process.

According to the low-dielectric and low-loss polyimide composite material, the mesoporous molecular sieve material is preferably mesoporous KIT-6, the structural advantages of moderate diameter, large specific surface area, high three-dimensional cubic pore channel order and the like are fully utilized, the polyimide material system is introduced after amino surface modification is carried out on the mesoporous molecular sieve material, compared with other known mesoporous molecular sieve materials, the polyimide composite material has the advantage of remarkably reducing the dielectric constant, and the surface amino modification mode also solves the problems that the mesoporous material cannot be uniformly dispersed with the polyimide system and the material is difficult to form a film in the prior art.

Detailed Description

Example 1

Putting 5g of phenylaminomethyltrimethylsilane into a 200ml polytetrafluoroethylene lining, then sequentially adding mesoporous KIT-6, acetonitrile and 15 wt% of dilute nitric acid, controlling the molar ratio of the phenylaminomethyltrimethylsilane to KIT-6 to acetonitrile to dilute nitric acid to be 0.2: 1: 0.5: 0.1, ultrasonically dispersing the mixed solution for 4 hours, then putting the mixed solution into a hydrothermal reaction kettle, heating the reaction kettle to 160 ℃, preserving heat for 36 hours, after the reaction is finished, cooling the reaction kettle to room temperature and filtering, fully washing the obtained precipitate with distilled water and ethanol sequentially, then drying in vacuum, then putting the dried product into a muffle furnace for roasting for 4 hours at 300 ℃, sanding to obtain the amino mesoporous KIT-6 nano material with 800nm surface amino modification, dispersing the amino mesoporous KIT-6 nano material into a methanol solvent, and keeping the dispersion concentration at 0.3 mol/L for later use.

Under the nitrogen atmosphere, 200ml of N, N-dimethylacetamide is added into a three-neck flask, the prepared methanol solution dispersed with amino mesoporous KIT-6 is slowly dripped through a peristaltic pump, and the dripping speed is controlled to be 2 ml/min; then adding 15g of pyromellitic dianhydride, fully and uniformly mixing, and reacting for 5h to obtain a uniform mixed solution containing amino mesoporous KIT-6 and a polyimide precursor solution, namely the polyimide composite material with low dielectric and low loss.

And preparing the low-dielectric and low-loss polyimide composite material solution into a polyimide film by casting by using a casting machine, namely preparing the low-dielectric and low-loss polyimide film.

Example 2

Putting 5g of phenylaminomethyltriethylsilane into a 200ml polytetrafluoroethylene lining, then sequentially adding mesoporous KIT-6, acetonitrile and 15 wt% of dilute nitric acid, controlling the molar ratio of phenylaminomethyltrimethylsilane to KIT-6 to acetonitrile to dilute nitric acid to be 0.2: 1: 0.5: 0.1, ultrasonically dispersing the mixed solution for 4 hours, then putting the mixed solution into a hydrothermal reaction kettle, heating the reaction kettle to 170 ℃, carrying out heat preservation reaction for 36 hours, cooling the reaction kettle to room temperature after the reaction is finished, filtering, sequentially washing the obtained precipitate with distilled water and ethanol, then carrying out vacuum drying, then putting the mixture into a muffle furnace, roasting for 4 hours at 350 ℃, carrying out sand grinding to obtain 800nm of amino mesoporous KIT-6 nano material with surface amino modification, and dispersing the amino mesoporous KIT-6 nano material into a methanol solvent, wherein the dispersion concentration is 0.3 mol/L for later use.

Under the nitrogen atmosphere, 200ml of N, N-dimethylacetamide solution is added into a three-neck flask, the methanol solution dispersed with the amino mesoporous KIT-6 nano material is slowly dripped through a peristaltic pump, and the dripping speed is controlled to be 3 ml/min; then adding 15g of pyromellitic dianhydride, fully and uniformly mixing, and reacting for 5h to obtain a uniform mixed solution containing amino mesoporous KIT-6 and a polyimide precursor solution, namely the polyimide composite material with low dielectric and low loss.

Example 3

Putting 5g of phenylaminomethyltrimethylsilane into a 200ml polytetrafluoroethylene lining, then sequentially adding mesoporous KIT-6, acetonitrile and 15 wt% of dilute nitric acid, controlling the molar ratio of phenylaminomethyltrimethylsilane to KIT-6 to acetonitrile to dilute nitric acid to be 0.2: 1: 0.5: 0.1, ultrasonically dispersing the mixed solution for 4 hours, then putting the mixed solution into a hydrothermal reaction kettle, heating the reaction kettle to 170 ℃, preserving the temperature for 36 hours, cooling the reaction kettle to room temperature after the reaction is finished, filtering, sequentially washing the obtained precipitate with distilled water and ethanol, then carrying out vacuum drying, roasting in a muffle furnace at 300 ℃ for 4 hours, sanding to obtain 600nm of amino mesoporous KIT-6 nano material with surface amino modification, and dispersing the amino mesoporous KIT-6 nano material into a methanol solvent, wherein the dispersion concentration is 0.3 mol/L for later use.

Under the nitrogen atmosphere, adding 200ml of N, N-dimethylacetamide solution into a three-neck flask, slowly dropwise adding the methanol solution dispersed with the amino mesoporous KIT-6 through a peristaltic pump, and controlling the dropwise adding speed to be 2 ml/min; then adding 17g of pyromellitic dianhydride, fully and uniformly mixing, and reacting for 5h to obtain a uniform mixed solution containing amino mesoporous KIT-6 and a polyimide precursor solution, namely the required low-dielectric and low-loss polyimide composite material.

Example 4

Putting 5g of phenylaminomethyltrimethylsilane into a 200ml polytetrafluoroethylene lining, then sequentially adding mesoporous KIT-6, acetonitrile and 15 wt% of dilute nitric acid, ultrasonically dispersing the mixed solution for 4h, then putting the mixed solution into a hydrothermal reaction kettle, heating the reaction kettle to 170 ℃, preserving the temperature for 36h, cooling the reaction kettle to room temperature after the reaction is finished, filtering, sequentially washing the obtained precipitate with distilled water and ethanol, then carrying out vacuum drying, roasting in a muffle furnace at 300 ℃ for 4h, sanding to obtain a 600nm mesoporous KIT-6 nano material with surface amino modification, and dispersing the mesoporous KIT-6 nano material into a methanol solvent, wherein the dispersion concentration is 0.4 mol/L for later use.

Under the nitrogen atmosphere, adding 200ml of N, N-dimethylacetamide solution into a three-neck flask, slowly dropwise adding the methanol solution dispersed with the amino mesoporous KIT-6 through a peristaltic pump, and controlling the dropwise adding speed to be 2 ml/min; then adding 20g of benzophenone tetracarboxylic dianhydride, fully and uniformly mixing, and reacting for 5h to obtain a uniform mixed solution containing amino mesoporous KIT-6 and a polyimide precursor solution, namely the polyimide composite material with low dielectric and low loss.

Example 5

The preparation of the polyimide composite material and the polyimide film prepared by the preparation method are the same as those in example 1, except that the mesoporous material is mesoporous MCM-41.

Example 6

The preparation of the polyimide composite material and the polyimide film prepared by the preparation method are the same as those in example 1, except that the mesoporous material is selected from mesoporous MCM-48.

Example 7

The preparation of the polyimide composite material and the polyimide film prepared from the polyimide composite material in this embodiment are the same as those in embodiment 1, except that the mesoporous material is selected from mesoporous FDU-15.

Example 8

Putting 5g of phenylaminomethyltrimethylsilane into a 200ml polytetrafluoroethylene lining, then sequentially adding mesoporous KIT-6, dichloromethane and 15 wt% of dilute nitric acid, controlling the molar ratio of phenylaminomethyltrimethylsilane to KIT-6: dichloromethane to dilute nitric acid to be 0.1: 1.2: 0.3: 0.15, ultrasonically dispersing the mixed solution for 4 hours, then putting the mixed solution into a hydrothermal reaction kettle, heating the reaction kettle to 180 ℃, preserving heat for 36 hours, cooling the reaction kettle to room temperature and filtering after the reaction is finished, fully washing the obtained precipitate with distilled water and ethanol sequentially, then drying in vacuum, then putting the dried product into a muffle furnace, roasting for 3 hours at 400 ℃, sanding to obtain a surface amino modified amino mesoporous KIT-6 nano material with the particle size of 500nm, and dispersing the nano material into a propanol solvent, wherein the dispersion concentration is 0.1 mol/L for later use.

Under the nitrogen atmosphere, 200ml of N, N-dimethylformamide is added into a three-neck flask, the prepared propanol solution dispersed with the amino mesoporous KIT-6 is slowly dripped through a peristaltic pump, and the dripping speed is controlled to be 2 ml/min; then adding 16g of monoether tetracid dianhydride, fully and uniformly mixing, and reacting for 5h to obtain a uniform mixed solution containing amino mesoporous KIT-6 and a polyimide precursor solution, namely the required low-dielectric and low-loss polyimide composite material.

Example 9

Putting 5g of phenylaminomethyltrimethylsilane into a 200ml polytetrafluoroethylene lining, then sequentially adding mesoporous KIT-6, toluene and 15 wt% of dilute nitric acid, controlling the molar ratio of phenylaminomethyltrimethylsilane to KIT-6: toluene to dilute nitric acid to be 0.3: 0.8: 0.7: 0.05, ultrasonically dispersing the mixed solution for 4 hours, then putting the mixed solution into a hydrothermal reaction kettle, heating the reaction kettle to 150 ℃, preserving heat for 36 hours, cooling the reaction kettle to room temperature and filtering after the reaction is finished, fully washing the obtained precipitate with distilled water and ethanol in sequence, then drying in vacuum, then putting the dried product into a muffle furnace, roasting for 3 hours at 400 ℃, sanding to obtain a surface amino modified amino mesoporous KIT-6 nano material with the particle size of 500nm, and dispersing the amino modified mesoporous KIT-6 nano material into an ethanol solvent, wherein the dispersion concentration is 0.6 mol/L for later use.

200ml of the mixture is added into a three-neck flask under the nitrogen atmosphereN, N-dimethylpropionamideSlowly dropwise adding the prepared ethanol solution dispersed with the amino mesoporous KIT-6 by a peristaltic pump, and controlling the dropwise adding speed to be 2 ml/min; then adding 17g of triphenyldiether tetracarboxylic dianhydride, fully and uniformly mixing, and reacting for 5h to obtain a uniform mixed solution containing amino mesoporous KIT-6 and a polyimide precursor solution, namely the polyimide composite material with low dielectric and low loss.

Comparative example 1

The preparation of the polyimide composite material and the polyimide film prepared by the preparation method of the polyimide composite material in the comparative example are different from those of example 4 only in that the amino group modification step of the mesoporous material in the step (1) is not performed, but the mesoporous KIT-6 is directly dispersed in a methanol solution and subjected to the treatment of the subsequent step (2), and the preparation of the subsequent polyimide film is performed.

Comparative example 2

The preparation of the polyimide composite material and the polyimide film prepared by the preparation method are the same as those in example 1, and the difference is only that the mesoporous material is mesoporous SBA-15.

Comparative example 3

The preparation of the polyimide composite material and the polyimide film prepared by the preparation method are the same as those in example 1, except that in the step (1), a silane coupling agent is selected for surface modification of the mesoporous material.

Comparative example 4

The preparation of the polyimide composite material and the polyimide film prepared by the preparation method are the same as those in example 1, except that in the step (1), the step of high-temperature hydrothermal synthesis is omitted, and the uniformly dispersed mixed solution is directly subjected to subsequent treatment.

Examples of the experiments

1. Dielectric properties

The dielectric constant and dielectric loss parameters of the materials prepared in examples 1 to 4 and comparative examples 1 to 8 were measured, respectively, with a frequency of 1GHz set, and the results are shown in table 1 below.

Table 1 dielectric property test results of materials

Numbering	Dielectric constant	Dielectric loss
			Example 1	2.2	0.0002
Example 2	2.4	0.0003
			Example 3	2.5	0.0004
Example 4	2.3	0.0003
			Example 5	2.5	0.0005
Example 6	2.4	0.0004
			Example 7	2.5	0.0005
Comparative example 1	3.0	0.0007
			Comparative example 2	2.6	0.0006
Comparative example 3	2.9	0.0006
			Comparative example 4	3.1	0.0009

The data show that the polyimide material obtained by the method for forming the surface-modified mesoporous material and uniformly blending the surface-modified mesoporous material with the polyimide precursor has the dielectric constant of less than 2.5, the dielectric loss of less than 0.0005 and better dielectric property.

In the prior art, the dielectric property of the product is not ideal in the scheme of directly preparing the polyimide material by using the mesoporous material and the scheme of preparing the polyimide material by using other common mesoporous materials; in contrast, in comparative example 3, only silane coupling was performed without amino modification, and in comparative example 4, the amino group could not be crosslinked with the material without performing the corresponding hydrothermal reaction, resulting in poor performance.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A method for preparing a low-dielectric and low-loss polyimide composite material is characterized by comprising the following steps:

(1) taking an aminosilane modifier, sequentially adding a mesoporous material, a reaction solvent and an acidic solution, uniformly dispersing, and carrying out hydrothermal reaction at the temperature of 150-; after the reaction is finished, collecting the precipitate, washing, drying and roasting to obtain an amino mesoporous material with the surface modified by amino, and dispersing the amino mesoporous material in an organic solvent for later use;

2. The method for preparing a low dielectric and low loss polyimide composite material as claimed in claim 1, wherein in the step (1), the mesoporous material comprises mesoporous KIT, FDU or MCM mesoporous material.

3. The method for preparing a low dielectric and low loss polyimide composite material as claimed in claim 1 or 2, wherein in the step (1), the aminosilane modifier comprises phenylaminomethyltrimethylsilane and/or phenylaminomethyltriethylsilane.

4. A method for preparing a low dielectric, low loss polyimide composite as claimed in any one of claims 1 to 3, wherein in said step (1), said aminosilane modifier, mesoporous material, acetonitrile and dilute nitric acid solution are present in a molar ratio of 0.1-0.3: 0.8-1.2: 0.3-0.7: 0.05-0.15.

5. The method as claimed in any one of claims 1 to 4, wherein the temperature of the baking step in step (1) is 200-400 ℃.

6. The method as claimed in any one of claims 1 to 5, wherein the step (1) further comprises a step of sand-grinding the mesoporous material with modified surface amino groups to a particle size of 500-2000 nm.

7. A method for preparing a low dielectric constant low loss polyimide composite material as claimed in any one of claims 1 to 6, wherein said organic solvent comprises methanol, ethanol and/or propanol, and the dispersion concentration of said amino mesoporous material in said organic solvent is controlled to be 0.1-0.6 mol/L in said step (1).

8. The method for preparing a low-dielectric low-loss polyimide composite material as claimed in any one of claims 1 to 7, wherein in the step (2), the mass ratio of the organic acid anhydride monomer to the amino group-containing mesoporous material is 3 to 4: 1.

9. a method for preparing a low dielectric, low loss polyimide composite as claimed in any one of claims 1 to 8, wherein in said step (2): the organic acid anhydride monomer comprises one or a mixture of more of pyromellitic dianhydride, monoether tetracarboxylic dianhydride, triphendiether tetracarboxylic dianhydride, biphenyl ether dianhydride and benzophenone tetracarboxylic dianhydride;

10. A low dielectric and low loss polyimide film prepared from the low dielectric and low loss polyimide composite material as claimed in any one of claims 1 to 9 by a conventional method.