阅读说明：本技术 一种带有大体积侧基的二胺单体及其制备方法和应用 (Diamine monomer with bulky side group and preparation method and application thereof ) 是由 张国平 张帆 李金辉 孙蓉 于 2019-10-10 设计创作，主要内容包括：本发明涉及一种带有大体积侧基的二胺单体及其制备方法和应用,所述二胺单体的结构如式(Ⅰ)所示。本发明涉及一种新型的二胺单体,其带有大体积侧基,将其用于聚酰亚胺的制备,制备得到的聚酰亚胺的自由体积大,可以降低分子链间的堆积,降低摩尔极化率,从而显著地降低聚酰亚胺的介电常数。将其用于微电子领域,是很好的层间介质材料,能够减少信号的串扰和迟滞。(The invention relates to a diamine monomer with a bulky side group, a preparation method and application thereof, wherein the structure of the diamine monomer is shown as a formula (I). The invention relates to a novel diamine monomer with a bulky side group, which is used for preparing polyimide, and the prepared polyimide has a large free volume, can reduce the accumulation among molecular chains, and reduce the molar polarizability, thereby remarkably reducing the dielectric constant of the polyimide. The material is used in the field of microelectronics, is a good interlayer dielectric material, and can reduce the crosstalk and the delay of signals.)

1. A diamine monomer with bulky side groups, wherein the diamine monomer has the structure shown in formula (I):

2. the method of claim 1, wherein the method comprises the steps of:

(1) reacting p-hydroxybenzaldehyde with triphenyl halogenated methane to obtain a product A;

(2) and (2) reacting the product A obtained in the step (1) with aniline and aniline hydrochloride to obtain the diamine monomer.

3. The method for preparing diamine monomer according to claim 2, wherein the triphenylmethyl halide in the step (1) comprises triphenylmethyl chloride, triphenylmethyl bromide or triphenylmethyl iodide;

preferably, the reaction of step (1) is carried out in an organic solvent containing potassium carbonate;

preferably, the organic solvent comprises N, N-dimethylformamide or N, N-dimethylacetamide;

preferably, the reaction of the step (1) is carried out under the protection of protective gas;

preferably, the protective gas comprises nitrogen;

preferably, the temperature of the reaction in step (1) is 120-150 ℃;

preferably, the reaction time of the step (1) is 18-30 h;

preferably, the reaction in step (1) is carried out to obtain a product A, and the post-treatment operation comprises removing the solvent by distillation under reduced pressure, and washing and drying the product A.

4. The method for producing diamine monomer according to claim 2 or 3, wherein the reacting of the product A with aniline and aniline hydrochloride in the step (2) is carried out by mixing and dissolving the product A with aniline and aniline hydrochloride, and then carrying out the reaction;

preferably, the mixing and dissolving are carried out under the protection of nitrogen;

preferably, the mixing and dissolving are carried out at 105-115 ℃;

preferably, the temperature of the reaction is 140-160 ℃;

preferably, the reaction time is 1-2 h;

preferably, after the diamine monomer is obtained in the step (2), performing post-treatment operation, wherein the post-treatment operation comprises vacuum distillation, solid dissolution, filtration, drying and recrystallization.

5. The method of producing diamine monomers of any of claims 2 to 4, comprising the steps of:

(1) reacting p-hydroxybenzaldehyde and triphenylchloromethane in N, N-dimethylformamide containing potassium carbonate at the temperature of 120-150 ℃ under the protection of nitrogen for 18-30h to obtain a product A;

(2) carrying out reduced pressure distillation on the product A obtained in the step (1) to remove the solvent, washing the product A with deionized water and carrying out vacuum drying;

(3) mixing and dissolving the treated product A obtained in the step (2) with aniline and aniline hydrochloride under the protection of nitrogen at 105-115 ℃, and reacting for 1-2h at 140-160 ℃;

(4) and (4) carrying out vacuum distillation on the product obtained in the step (3), dissolving the solid, filtering, drying and recrystallizing to obtain the diamine monomer.

6. A polyimide film with a low dielectric constant is characterized in that the structural general formula of the polyimide is shown as formula (II):

wherein n is an integer greater than or equal to 1; x is a tetravalent aromatic hydrocarbon group;

the structure of Y is shown in formula (III), and the dotted line represents the access site:

7. the low dielectric constant polyimide film of claim 6, wherein X is selected from one or more of the following formulae, and the dotted line represents an access site:

8. the method of preparing a low dielectric constant polyimide film according to claim 6 or 7, comprising the steps of:

(1) reacting a diamine monomer with dianhydride containing an X structure to obtain polyamic acid; the diamine monomer comprises the diamine monomer of claim 1;

(2) and (2) coating the polyamic acid obtained in the step (1) and performing thermal imidization to obtain the polyimide film with the low dielectric constant.

9. The method of preparing a low dielectric constant polyimide film according to claim 8, wherein the molar ratio of the diamine monomer to the dianhydride comprising the structure X in step (1) is 1 (0.9-1.1);

preferably, the reaction in step (1) is carried out under the protection of nitrogen;

preferably, the reaction of step (1) is carried out in a polar aprotic organic solvent;

preferably, the reaction temperature in the step (1) is-10-40 ℃;

preferably, the reaction time of the step (1) is 0.5-72 h;

preferably, the procedure of raising the temperature for thermal imidization in step (2) is: heating to 50-180 deg.C at 20-30 deg.C for 10-240 min; then the temperature is increased to 180 ℃ and 250 ℃ for 10-240 min; finally, the temperature is raised to 380 ℃ of 250 ℃ for 10-360 min.

10. Use of the low dielectric constant polyimide film of claim 6 or 7 in an interlayer dielectric material in the field of microelectronics.

Technical Field

The invention belongs to the technical field of non-metallic functional material manufacturing, relates to a diamine monomer, a preparation method and application thereof, and particularly relates to a diamine monomer with a large-volume side group, and a preparation method and application thereof.

Background

As the chip package size in the microelectronic field becomes smaller, the distance between the wires is also gradually reduced, and the wiring density is increased. The variation of current in the wires causes a variation of a surrounding electromagnetic field, and when the distance between the wires is reduced to a certain extent, an induced current is generated in the adjacent wires, which phenomenon is called crosstalk, and the crosstalk lowers the reliability of data transmission. In addition, when the distance between adjacent wires is small enough, if different voltages are applied to the two wires, the two wires form a capacitor. The variation in circuit density and device size causes an increase in inter-wire capacitance and resistance of metal wiring, and thus the induced RC delay. The signal delay of the interconnect line can be calculated by the following equation:

t is signal delay time; r-resistance, C-capacitance; ρ — interconnect resistance; epsilon-dielectric constant of the insulating material; epsilon₀-vacuum dielectric constant; l is the length of the wire; t is the thickness of the lead; p-wire spacing. Several interlayer insulating materials commonly used at present are Polyimide (PI), Polybenzoxazole (PBO) and benzocyclobutene (BCB). Polyimide PI has the longest application history and is studied most fully, and compared with the other two materials, the PI has lower cost. Meanwhile, the polyimide has good comprehensive properties such as heat resistance, radiation resistance, mechanical property and electrical insulation property. The dielectric constant of the traditional polyimide Kapton film is 3.1-3.6, and the requirement of the 5G era can not be met more and more. Therefore, low dielectric polyimide PIs are receiving extensive attention and research.

The general methods for reducing the dielectric constant of polyimide mainly include: 1. atoms with low polarizability, such as fluorine atoms, are introduced, because the fluorine atoms have high electronegativity and low polarization degree, the dielectric constant can be reduced; 2. the air micropore structure is introduced, because the air has the lowest dielectric constant of 1, the air micropore can be etched by adding particles with micropores or by a chemical method; 3. bulky side groups are introduced.

CN108329689A discloses a polyimide porous membrane with low dielectric constant and a preparation method thereof. The method has the characteristics of simple equipment, mild condition, low cost, short period, simple and convenient operation process and technology and the like, and because the water drops are selected as the pore-forming template, the method has the advantage of low cost and does not need additional steps for removal, the operation steps are simplified, and meanwhile, the damage to the structure and the performance of the polyimide film is avoided. In addition, the structure of the polyimide porous membrane can be adjusted by changing the film forming conditions, so that the dielectric constant of the film can be adjusted and controlled. Compared with a nonporous polyimide film, the polyimide porous film prepared by the method has obviously reduced dielectric constant.

CN109942851A discloses a polyimide hybrid film with a low dielectric constant and application thereof, which comprises a fluorination process of porous nanoparticles, a hybridization process of fluorinated porous nanoparticles and a polyimide precursor solution, and a film forming process of a hybrid system. The porous nano particles are one or more of silicon dioxide, zeolite, MCM-41 and SBA-15 molecular sieves. The dielectric constant of the porous nano particles is low, and the dielectric constant loss can be further reduced after the surface fluorination treatment. The fluorinated porous nanoparticles are compounded with the polyimide precursor solution, so that the fluorinated porous nanoparticles have good dispersibility in the final polyimide film, and the dielectric constant of the hybrid film is reduced.

However, the above prior art has the following disadvantages: 1) the cost for synthesizing polyimide by using the fluorine-containing monomer is high, and the reduction of the dielectric constant is limited; 2) the process for preparing the air micropores to reduce the dielectric constant is complex, difficult to control and high in production cost; the structure and the aperture of the pores are not easy to control; the material has poor mechanical property and lower mechanical strength; 3) the existing method for synthesizing the diamine monomer with the bulky side group has complex steps and is not beneficial to operation. Therefore, it is very useful to develop a diamine monomer which is easy to synthesize and to prepare a polyimide having a low dielectric constant using the same.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a diamine monomer with a bulky side group, a preparation method and application thereof, and particularly provides a novel aromatic diamine monomer, a preparation method thereof, a polyimide film with a low dielectric constant, a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a diamine monomer with bulky side groups, wherein the diamine monomer has a structure represented by formula (i):

the diamine monomer has bulky side groups, and is used for preparing polyimide, so that the prepared polyimide has large free volume, can reduce the accumulation among molecular chains, and reduce the molar polarizability, thereby remarkably reducing the dielectric constant of the polyimide.

In a second aspect, the present invention provides a method for preparing a diamine monomer as described above, comprising the steps of:

(1) reacting p-hydroxybenzaldehyde with triphenyl halogenated methane to obtain a product A;

(2) and (2) reacting the product A obtained in the step (1) with aniline and aniline hydrochloride to obtain the diamine monomer.

The chlorine atom in the triphenylchloromethane can be replaced by any halogen atom capable of reacting with p-hydroxybenzaldehyde, and the reaction mechanism and the performance of the product obtained by the reaction are consistent.

Preferably, the triphenylmethyl halide of step (1) comprises triphenylmethyl chloride, triphenylmethyl bromide or triphenylmethyl iodide.

Preferably, the reaction in step (1) is carried out in an organic solvent containing a strong basic substance such as potassium carbonate.

Preferably, the organic solvent comprises N, N-dimethylformamide or N, N-dimethylacetamide.

Preferably, the reaction of step (1) is carried out under the protection of a protective gas.

Preferably, the protective gas comprises nitrogen.

Preferably, the temperature of the reaction in step (1) is 120-.

Preferably, the reaction time in step (1) is 18-30h, such as 18h, 20h, 22h, 23h, 24h, 25h, 26h, 28h or 30h, etc.

Preferably, the reaction in step (1) is carried out to obtain a product A, and the post-treatment operation comprises removing the solvent by distillation under reduced pressure, and washing and drying the product A.

The post-treatment operation specifically comprises the following steps: and distilling the product A under reduced pressure to remove the solvent, pouring the residue into deionized water, soaking, filtering, repeatedly washing, and then carrying out vacuum drying at the temperature of about 100 ℃ to obtain a precipitate.

Preferably, the step (2) of reacting the product a with aniline and aniline hydrochloride means that the product a is mixed with aniline and aniline hydrochloride to be dissolved and then reacted.

Preferably, the mixing and dissolving are carried out under the protection of nitrogen.

Preferably, the mixing and dissolving is carried out at 105-115 ℃, such as 105 ℃, 107 ℃, 108 ℃, 109 ℃, 110 ℃, 112 ℃ or 115 ℃.

Preferably, the temperature of the reaction is 140-160 ℃, such as 140 ℃, 145 ℃, 150 ℃, 155 ℃ or 160 ℃, etc.

Preferably, the reaction time is 1-2h, such as 1h, 1.2h, 1.4h, 1.5h, 1.8h, 2h, or the like.

Preferably, after the diamine monomer is obtained in the step (2), performing post-treatment operation, wherein the post-treatment operation comprises vacuum distillation, solid dissolution, filtration, drying and recrystallization.

As a preferred embodiment of the present invention, the method for preparing the diamine monomer comprises the following steps:

(1) reacting p-hydroxybenzaldehyde and triphenylchloromethane in N, N-dimethylformamide containing potassium carbonate at the temperature of 120-150 ℃ under the protection of nitrogen for 18-30h to obtain a product A;

(2) carrying out reduced pressure distillation on the product A obtained in the step (1) to remove the solvent, washing the product A with deionized water and carrying out vacuum drying;

(3) mixing and dissolving the treated product A obtained in the step (2) with aniline and aniline hydrochloride under the protection of nitrogen at 105-115 ℃, and reacting for 1-2h at 140-160 ℃;

(4) and (4) carrying out vacuum distillation on the product obtained in the step (3), dissolving the solid, filtering, drying and recrystallizing to obtain the diamine monomer.

The diamine monomer has relatively low synthesis cost, simple synthesis steps and easy operation.

In a third aspect, the present invention provides a polyimide film with a low dielectric constant, wherein the structural general formula of the polyimide is represented by formula (ii):

wherein n is an integer greater than or equal to 1; x is a tetravalent aromatic hydrocarbon group.

The structure of Y is shown in formula (III), and the dotted line represents the access site:

the low dielectric constant of the polyimide film according to the present invention means that the dielectric constant is 3.0 or less.

Preferably, X is selected from one or more of the following structural formulae, the dotted line representing the access site:

the polyimide in the polyimide film has bulky side groups, so that the free volume is large, the accumulation of molecular chains is reduced, and the molar polarizability is reduced, so that the dielectric constant of the polyimide film is remarkably reduced to less than 3.0.

The X is selected from a plurality of structural formulas, which means that the X structures in different polyimide chains in the prepared polyimide film are different.

In a fourth aspect, the present invention provides a method for preparing the polyimide film with a low dielectric constant as described above, the method comprising the steps of:

(1) reacting a diamine monomer with dianhydride containing an X structure to obtain polyamic acid; the diamine monomer comprises the diamine monomer of claim 1;

(2) and (2) coating the polyamic acid obtained in the step (1) and performing thermal imidization to obtain the polyimide film with the low dielectric constant.

Preferably, the molar ratio of diamine monomer to dianhydride containing the X structure in step (1) is 1 (0.9-1.1), such as 1:0.9, 1:1 or 1: 1.1.

Preferably, the reaction of step (1) is carried out under nitrogen protection.

Preferably, the reaction of step (1) is carried out in a polar aprotic organic solvent.

Preferably, the reaction temperature in the step (1) is-10 to 40 ℃, such as-10 ℃, 0 ℃, 10 ℃, 20 ℃, 30 ℃ or 40 ℃.

Preferably, the reaction time in step (1) is 0.5-72h, such as 0.5h, 1h, 5h, 10h, 20h, 30h, 40h, 50h, 65h or 72h, etc.

Preferably, the procedure of raising the temperature for thermal imidization in step (2) is: heating to 50-180 deg.C at 20-30 deg.C for 10-240 min; then the temperature is increased to 180 ℃ and 250 ℃ for 10-240 min; finally, the temperature is raised to 380 ℃ of 250 ℃ for 10-360 min.

The specific operation for preparing the polyimide film is as follows: coating the prepared polyamic acid solution on a glass plate by a spin coating method, heating the glass plate on a hot plate at 70-90 ℃ for 2-10min to volatilize the solvent to obtain a coating film with the film thickness of 20-30 mu m, and then placing the coating film in a nitrogen oven to carry out thermal imidization by the temperature programming to finally obtain the polyimide film.

In a fifth aspect, the invention provides an application of the polyimide film with low dielectric constant in an interlayer dielectric material in the field of microelectronics. In particular to an ILD interlayer dielectric material and an RDL rewiring layer applied to electronic packaging.

Compared with the prior art, the invention has the following beneficial effects:

the diamine monomer has the advantages of simple preparation method, easy operation and low cost, and the structure of the diamine monomer has a bulky side group, so that the diamine monomer is used for preparing the polyimide, the free volume of the prepared polyimide is large, the accumulation among molecular chains of the polyimide is reduced, the molar polarizability of the polyimide is reduced, and the dielectric constant of the polyimide is remarkably reduced. The material is used in the field of microelectronics, is a good interlayer dielectric material, and can reduce the crosstalk and the delay of signals.

Drawings

FIG. 1 is a graph showing an infrared spectrum of a polyimide film obtained in example 3;

FIG. 2 is a graph showing an IR spectrum of a polyimide film obtained in example 4;

FIG. 3 is a graph showing the IR spectrum of a polyimide film obtained in example 5.

Detailed Description

To further illustrate the technical means and effects of the present invention, the following further describes the technical solution of the present invention with reference to the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.