A film formation rate matching method for C-type parylene dimer

Abstract

The present invention provides a method for matching the film formation rate of C-type polyparaxylene dimer, comprising the following steps: S100, constructing a sublimation rate calculation formula, a cracking rate calculation formula, and a film formation rate calculation formula; S200, using the sublimation rate calculation formula, the cracking rate calculation formula, and the film formation rate calculation formula to respectively calculate the sublimation rate, the cracking rate, and the film formation rate, and by adjusting the corresponding sublimation temperature, the cracking temperature, and the film formation temperature, achieving equality of the sublimation rate, the cracking rate, and the film formation rate, thereby achieving speed matching in the film formation process of C-type polyparaxylene dimer. Utilizing the present invention, the film formation efficiency of C-type polyparaxylene dimer can be significantly improved, the product processing time can be shortened by more than 40%, the raw material utilization rate of C-type polyparaxylene dimer can be improved, and the film formation quality of C-type polyparaxylene dimer can be improved, and the C residual substances in the film formation process can be significantly reduced.

Description

Technical Field

[0001] The invention relates to a film forming rate matching method for a C-type polyparaxylene dimer, which is applicable to a film layer deposition process and quality control of polyparaxylene materials. Background Art

[0002] Millimeter-wave technology, due to its abundant spectrum resources, support for high-speed data transmission, and strong anti-interference capabilities, is widely used in satellite communications and radar. Millimeter-wave radar has strong penetration and is minimally affected by extreme weather conditions, making it suitable for a wide range of applications. Its miniaturization and low power consumption have led to its widespread use in satellite communications and airborne systems, making it a major trend in current and future communications technology development.

[0003] As the application scope of millimeter-wave technology expands, related products are directly exposed to industrial and natural environments. This results in harsh operating environments, severely impacting product performance, reliability, and lifespan, and placing stringent demands on product protection. Parylene film, due to its low dielectric constant, low loss, excellent solvent resistance, pollution-free film formation process, and dense, non-porous film layer, can achieve excellent protection even with thin film thicknesses, making it an ideal protective material for millimeter-wave products, meeting both the functional and protection requirements of millimeter-wave products. However, due to the complex vapor deposition process of parylene film, quantitative analysis of the dimer sublimation rate, dimer fragmentation rate, and monomer polymerization rate during the film formation process is extremely difficult. Furthermore, modeling the film formation process is also difficult, resulting in a mismatch between the dimer sublimation rate, dimer fragmentation rate, and film formation rate. This results in long film formation times, low raw material utilization, and high costs for parylene materials, failing to meet users' growing demand for high-efficiency, low-cost film formation.

[0004] Currently, the rate matching of the polyparaxylene film formation process is mainly carried out using the process experiment method. This method has improved the film formation rate of the polyparaxylene material to a certain extent. However, since the experimental process does not take into account the physical and chemical processes and characteristics of the sublimation, cracking and film formation of the polyparaxylene dimer material, the rate matching of the sublimation, cracking and film formation of the polyparaxylene material is still poor and cannot meet user needs. Judging from the currently published papers and patents, there is no technology for matching the film formation rate of the polyparaxylene material. Most technologies focus on the performance analysis of the polyparaxylene material in millimeter wave circuits and the influence of film forming pressure, sublimation temperature, cracking temperature, etc. on the film performance and rate. None of them involve the matching technology of the sublimation rate, cracking rate and film formation rate in the vapor deposition process of the polyparaxylene material. For example, the paper "Characterization of Parylene Deposition Process for the Passivation of Organic Light Emitting Diodes" studies the relationship between process parameters such as sublimation temperature and deposition temperature and film deposition rate; and the paper "Deposition and Polymerization Process of Parylene Films and Its Influencing Factors" describes the relationship between the sublimation of the dimer, the cracking rate, deposition pressure, and substrate temperature, as well as the film deposition rate, structure, and performance. These related works all simply verified the relationship between relevant process parameters and film deposition rate from a process experimental perspective, and none of them addressed the matching technology of sublimation rate, cracking rate, and film deposition rate during the deposition process of parylene films. Summary of the Invention

[0005] The present invention aims to provide a film formation rate matching method for C-type polyparaxylene dimer, so as to solve the problem of mismatch among dimer sublimation rate, dimer cracking rate and film formation rate in the film formation process of C-type polyparaxylene dimer, achieve matching among sublimation rate, cracking rate and film formation rate in the dimer film formation process, improve polyparaxylene film formation efficiency, equipment utilization, film layer quality and raw material utilization, and reduce film formation cost and film formation time.

[0006] The present invention provides a method for matching the film formation rate of a C-type parylene dimer, comprising the following steps:

[0007] S100, respectively constructing a sublimation rate calculation formula, a cracking rate calculation formula, and a film formation rate calculation formula;

[0008] S200, using the sublimation rate calculation formula, cracking rate calculation formula and film formation rate calculation formula to respectively calculate the sublimation rate, cracking rate and film formation rate, and by adjusting the corresponding sublimation temperature, cracking temperature and film formation temperature, the sublimation rate, cracking rate and film formation rate are made equal, thereby achieving speed matching in the film formation process of type C paraxylene dimer.

[0009] Furthermore, step S100 includes the following sub-steps:

[0010] S101, collecting DSC curve and DTG curve of C-type parylene dimer;

[0011] S102, constructing a sublimation temperature model for C-type parylene dimer;

[0012] S103, calculating the maximum sublimation temperature by combining the DSC curve and the sublimation temperature model;

[0013] S104, constructing a cracking temperature model for C-type parylene dimer;

[0014] S105, calculating the maximum cracking temperature by combining the DTG curve and the cracking temperature model;

[0015] S106, constructing an amorphous macromolecular chain model of C-type parylene dimer;

[0016] S107, determine the maximum film-forming temperature and maximum film-forming pressure using the amorphous macromolecular chain model;

[0017] S108, determining the film forming time through a film forming experiment based on the maximum sublimation temperature, the maximum cracking temperature, the maximum film forming temperature, and the maximum film forming pressure;

[0018] S109, constructing a sublimation rate calculation formula using the film forming time;

[0019] S110, constructing a cracking rate calculation formula based on the maximum cracking temperature;

[0020] S111 , constructing a film forming rate calculation formula in combination with the maximum film forming temperature and the maximum film forming pressure.

[0021] Furthermore, in step S102, the sublimation temperature model of C-type parylene dimer is constructed and expressed as:

[0022]

[0023] Where, β i is the heating rate, K / min; T pi is the peak temperature of the DSC curve at different heating rates, K; T p0is the temperature when the heating rate approaches 0, i.e. the maximum sublimation temperature, in K; b, c, and d are the sublimation temperature model coefficients.

[0024] Furthermore, the method for solving the maximum sublimation temperature in step S103 is:

[0025] (1) Substituting the sublimation temperature peaks of the DSC curves at different heating rates into the sublimation temperature model to obtain a linear equation system;

[0026] (2) Solve the linear equations to obtain the temperature T when the heating rate approaches 0 p0 , that is, the maximum sublimation temperature.

[0027] Furthermore, in step S104, the method for constructing the cracking temperature model of C-type parylene dimer is:

[0028] (1) Use Gaussview to establish the model of C-type parylene dimer and monomer, and optimize the structure to minimize the energy;

[0029] (2) The optimized C-type parylene dimer and monomer models were imported into Shermo software to calculate the free energy change Δ r G;

[0030] (3) Change the free energy to Δ r Substitute G into the theoretical cracking rate equation to obtain the cracking temperature model, which is expressed as:

[0031]

[0032] Where, E a is the apparent activation energy of cracking, kJ / mol; k TST is the theoretically calculated fragmentation rate constant, s -1 ; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ; A is the pre-exponential factor of the cleavage reaction; T 裂解 is the maximum cracking temperature, K.

[0033] Furthermore, in step S105, the method for solving the maximum cracking temperature is:

[0034] (1) The peak cracking temperature of the DTG curve at different heating rates was introduced into the Kissinger equation and the Ozawa equation, and the pre-exponential factor A of the cracking reaction and the apparent activation energy E of the cracking reaction were obtained through regression analysis. a ;

[0035] (2) Calculate the cracking rate constant k by combining the gas decomposition rate equation under ideal conditions TST ;

[0036] (3) Binding cleavage rate constant k TST , the pre-exponential factor A of the cleavage reaction and the apparent activation energy E of the cleavage reaction a , calculate the maximum cracking temperature T 裂解 .

[0037] Furthermore, in step S106, the method for constructing the amorphous macromolecular chain model of C-type parylene dimer is:

[0038] (1) Construct a macromolecular model of C-type parylene dimer with a chain length of 100 to 1200 structural units and ensure that the macromolecular model has the lowest energy;

[0039] (2) Inserting macromolecular models of C-type parylene dimers with different chain lengths into amorphous cells to construct an amorphous model of C-type parylene dimers;

[0040] (3) Under different pressures, the amorphous model is structurally optimized by cellular compression so that the molecular density of the amorphous model reaches a required value;

[0041] (4) Annealing the amorphous model after structural optimization to eventually form multiple amorphous macromolecular chain models.

[0042] Furthermore, in step S109, the sublimation rate calculation formula is expressed as:

[0043]

[0044] Where, v 升华 is the sublimation rate, g / h; m 二聚体 is the mass of C-type parylene dimer, g; t is the film formation time, h.

[0045] Furthermore, in step S110, the method for constructing a cracking rate calculation formula in combination with the maximum cracking temperature is:

[0046] (1) The pre-exponential factor A of the cleavage reaction and the apparent activation energy E of the cleavage reaction are a Substituting into the Arrhenius equation, we get the equation for the cleavage rate constant:

[0047]

[0048] (2) the maximum cracking temperature T 裂解 Substitute into the cleavage rate constant equation to calculate the cleavage rate constant k1;

[0049] (3) Determine the concentration of C-type parylene dimer, expressed as:

[0050] c=P 成膜 / RT裂解

[0051] Where, c is the molar concentration of C-type polyparaxylene dimer, mol / L; P 成膜 is the maximum film-forming pressure; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ;

[0052] (4) Combined with the cleavage rate constant k1 and the concentration c of C-type polyparaxylene dimer, the cleavage rate of C-type polyparaxylene dimer is calculated:

[0053] v 裂解 =ck1

[0054] Where, v 裂解 is the cracking rate, mol / (L s); c is the molar concentration of C-type p-xylene dimer, mol / L; k1 is the cracking rate constant, s -1 .

[0055] Furthermore, in step S111, a method for constructing a film forming rate calculation formula by combining the maximum film forming temperature and the maximum film forming pressure is as follows:

[0056] (1) Change the free energy to Δ r G. Maximum film forming temperature T 成膜 And the maximum film forming pressure P 成膜 Substituting the following formula, we can obtain the rate constant k2 of C-type polyparaxylene dimer film formation:

[0057]

[0058] Where σ is the reaction path degeneracy, which is 1 for macromolecular systems; κ is the tunneling effect correction coefficient, which is 1; k b is the Boltzmann constant, 1.381×10 -23 J / K; h is Planck's constant, 6.62×10 -34 J·s; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ; Δ r G is the free energy change, kJ / mol; T 成膜 is the maximum film forming temperature, K; P 成膜 is the maximum film forming pressure, unit bar; N A is the number of molecules in 1 mol of a substance, 6.02×10 23 ;

[0059] (2) Calculate the film forming rate:

[0060] ν 成膜 =ck2

[0061] Where, ν 成膜 is the film formation rate, mol / (L s); c is the molar concentration of C-type p-xylene dimer, mol / L; k2 is the rate constant k2 when C-type poly-p-xylene dimer forms a film, s -1 .

[0062] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0063] By utilizing the present invention, the film-forming efficiency of C-type polyparaxylene dimer can be significantly improved, the product processing time can be shortened by more than 40%, the raw material utilization rate of C-type polyparaxylene dimer can be improved, and the film-forming quality of C-type polyparaxylene dimer can be improved at the same time, and the C residual matter in the film-forming process can be greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0065] Figure 1 Flowchart of the film formation rate matching method for C-type polyparaxylene dimer in an embodiment of the present invention.

[0066] Figure 2 This is a flow chart for constructing the sublimation rate calculation formula, the cracking rate calculation formula, and the film formation rate calculation formula in the embodiment of the present invention.

[0067] Figure 3 Schematic diagram of the construction of an amorphous macromolecular chain model and structural optimization of a C-type polyparaxylene dimer in an embodiment of the present invention.

[0068] Figure 4 Schematic diagram of the statistical analysis of the maximum film-forming temperature of C-type polyparaxylene dimer in an embodiment of the present invention.

[0069] Figure 5 Schematic diagram of statistical analysis of the maximum film-forming pressure of C-type polyparaxylene dimer in an embodiment of the present invention. DETAILED DESCRIPTION

[0070] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0071] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0072] Example

[0073] like Figure 1 As shown, this embodiment provides a film formation rate matching method for C-type parylene dimer, comprising the following steps:

[0074] S100, respectively constructing the sublimation rate calculation formula, the cracking rate calculation formula and the film formation rate calculation formula; Figure 2 As shown, it specifically includes the following sub-steps:

[0075] S101, collecting DSC curves and DTG curves of C-type polyparaxylene dimer; in this embodiment, the DSC curves and DTG curves of C-type polyparaxylene dimer are collected at four different heating rates of 5K / min, 10K / min, 15K / min, and 20K / min, and the test temperature range is 30-600°C.

[0076] S102, construct a sublimation temperature model for C-type parylene dimer, expressed as:

[0077]

[0078] Where, β i is the heating rate, K / min; T pi is the peak temperature of the DSC curve at different heating rates, K; T p0 is the temperature when the heating rate approaches 0, i.e. the maximum sublimation temperature, in K; b, c, and d are the sublimation temperature model coefficients.

[0079] S103, combining the DSC curve and the sublimation temperature model to determine the maximum sublimation temperature:

[0080] (1) Substituting the sublimation temperature peaks of the four groups of DSC curves with different heating rates into the sublimation temperature model, a linear equation system is obtained:

[0081] 453.9 = T p0 +5b+25c+125d

[0082] 456.6 = T p0 +10b+100c+1000d

[0083] 459.4 = T p0 +15b+225c+3375d

[0084] 463.1 = T p0 +20b+400c+8000d

[0085] (2) Solve the linear equations to obtain the temperature T when the heating rate approaches 0 p0 , that is, the maximum sublimation temperature.

[0086] S104, construct a cracking temperature model for C-type parylene dimer:

[0087] (1) Use Gaussview to establish the model of C-type parylene dimer and monomer, and optimize the structure to minimize the energy;

[0088] (2) The optimized C-type parylene dimer and monomer models were imported into Shermo software to calculate the free energy change Δ r G.

[0089] (3) Change the free energy to Δ r Substitute G into the theoretical cracking rate equation to obtain the cracking temperature model, which is expressed as:

[0090]

[0091] Where, E a is the apparent activation energy of cracking, kJ / mol; k TST is the theoretically calculated fragmentation rate constant, s -1 ; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ; A is the pre-exponential factor of the cleavage reaction; T 裂解 is the maximum cracking temperature, K.

[0092] S105, combining the DTG curve and the cracking temperature model to solve the maximum cracking temperature:

[0093] (1) The peak values ​​of the cracking temperatures of the DTG curves at four different heating rates were substituted into the Kissinger equation and the Ozawa equation. The pre-exponential factor A of the cracking reaction and the apparent activation energy E of the cracking reaction were obtained through regression analysis. a .

[0094] (2) Calculate the cracking rate constant k by combining the gas decomposition rate equation under ideal conditions TST .

[0095] (3) Binding cleavage rate constant k TST , the pre-exponential factor A of the cleavage reaction and the apparent activation energy E of the cleavage reaction a , calculate the maximum cracking temperature T 裂解 .

[0096] S106, construct an amorphous macromolecular chain model of C-type parylene dimer, such as Figure 3 As shown:

[0097] (1) Construct a macromolecular model of C-type parylene dimer with a chain length of 100 to 1200 structural units and ensure that the macromolecular model has the lowest energy;

[0098] (2) Inserting macromolecular models of C-type parylene dimers with different chain lengths into amorphous cells to construct an amorphous model of C-type parylene dimers; for example:

[0099] Contains 400 structural units, which can be realized as a single chain of 400 structural units (1*400), two chains of 200 structural units (2*200), or four chains of 100 structural units (4*100);

[0100] A cell containing 1200 structural units can be constructed using the patterns of 1*1200, 2*600, 3*400, 4*300, and 6*200;

[0101] Amorphous models of various chain lengths were constructed using the above method.

[0102] (3) Under different pressures, the amorphous model is structurally optimized by cellular compression. In this embodiment, 0 and 2×10 -10 The pressure of 0.1, 0.2, 0.3, 0.4 and 0.5 GPa is applied for a processing time of 100 ps to compress the cells in the amorphous model and increase the molecular density so that the molecular density of the amorphous model reaches the required value, such as 1.2 to 1.35 g / cm 3 .

[0103] (4) Annealing treatment is performed on the amorphous model after structural optimization. In this embodiment, the temperature of the cells in the amorphous model is first raised to 600K and then gradually cooled to 300K. The kinetic equilibrium time for each step is 40 to 60 ps, ​​thereby eliminating the unreasonable structure of the amorphous model and finally forming 100 to 200 amorphous macromolecular chain models.

[0104] S107, using the amorphous macromolecular chain model to determine the maximum film forming temperature and the maximum film forming pressure; that is, statistically analyzing the temperature and pressure distribution of the amorphous macromolecular chain model to obtain the maximum film forming temperature and the maximum film forming pressure, such as Figure 4 、 Figure 5 shown.

[0105] S108, determining the film forming time through a film forming experiment based on the maximum sublimation temperature, the maximum cracking temperature, the maximum film forming temperature, and the maximum film forming pressure;

[0106] S109, constructing a sublimation rate calculation formula using the film forming time, expressed as:

[0107]

[0108] Where, v 升华 is the sublimation rate, g / h; m 二聚体 is the mass of C-type parylene dimer, g; t is the film formation time, h.

[0109] S110, constructing a cracking rate calculation formula based on the maximum cracking temperature:

[0110] (1) The pre-exponential factor A of the cleavage reaction and the apparent activation energy E of the cleavage reaction are a Substituting into the Arrhenius equation, we get the equation for the cleavage rate constant:

[0111]

[0112] (2) the maximum cracking temperature T 裂解 Substitute into the cleavage rate constant equation to calculate the cleavage rate constant k1;

[0113] (3) Determine the concentration of C-type parylene dimer, expressed as:

[0114] c=P 成膜 / RT 裂解

[0115] Where, c is the molar concentration of C-type polyparaxylene dimer, mol / L; P 成膜 is the maximum film-forming pressure; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 .

[0116] (4) Combined with the cleavage rate constant k1 and the concentration c of C-type polyparaxylene dimer, the cleavage rate of C-type polyparaxylene dimer is calculated:

[0117] υ 裂解 =ck1

[0118] Where, 裂解 is the cracking rate, mol / (L s); c is the molar concentration of C-type p-xylene dimer, mol / L; k1 is the cracking rate constant, s -1 .

[0119] S111, constructing a film forming rate calculation formula based on the maximum film forming temperature and the maximum film forming pressure:

[0120] (1) Change the free energy to Δ r G. Maximum film forming temperature T 成膜 And the maximum film forming pressure P 成膜 Substituting into the following formula, we can obtain the rate constant k2 of film formation of C-type polyparaxylene dimer.

[0121]

[0122] Where σ is the reaction path degeneracy, which is generally 1 for macromolecular systems; κ is the tunneling effect correction coefficient, which is 1; k b is the Boltzmann constant, 1.381×10 -23 J / K; h is Planck's constant, 6.62×10 -34 J·s; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ; Δ r G is the free energy change, kJ / mol; T 成膜 is the maximum film forming temperature, K; P 成膜 is the maximum film forming pressure, unit bar; N A is the number of molecules in 1 mol of a substance, 6.02×10 23 .

[0123] (2) Calculate the film forming rate:

[0124] ν 成膜 =ck2

[0125] Where, ν 成膜 is the film formation rate, mol / (L s); c is the molar concentration of C-type p-xylene dimer, mol / L; k2 is the rate constant k2 when C-type poly-p-xylene dimer forms a film, s -1 .

[0126] S200, using the sublimation rate calculation formula, cracking rate calculation formula and film formation rate calculation formula to respectively calculate the sublimation rate, cracking rate and film formation rate, and by adjusting the corresponding sublimation temperature, cracking temperature and film formation temperature, the sublimation rate, cracking rate and film formation rate are made equal, thereby achieving speed matching in the film formation process of type C paraxylene dimer.

[0127] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A film forming rate matching method for C-type parylene dimer, characterized in that: The steps include: S100, respectively constructing a sublimation rate calculation formula, a cracking rate calculation formula, and a film formation rate calculation formula; S200, using the sublimation rate calculation formula, the cracking rate calculation formula, and the film formation rate calculation formula to respectively calculate the sublimation rate, the cracking rate, and the film formation rate, and adjusting the corresponding sublimation temperature, the cracking temperature, and the film formation temperature to achieve equality among the sublimation rate, the cracking rate, and the film formation rate, thereby achieving speed matching in the film formation process of type C para-xylene dimer; Step S100 includes the following sub-steps: S101, collecting DSC curve and DTG curve of C-type parylene dimer; S102, constructing a sublimation temperature model for C-type parylene dimer; S103, calculating the maximum sublimation temperature by combining the DSC curve and the sublimation temperature model; S104, constructing a cracking temperature model for C-type parylene dimer; S105, calculating the maximum cracking temperature by combining the DTG curve and the cracking temperature model; S106, constructing an amorphous macromolecular chain model of C-type parylene dimer; S107, determine the maximum film-forming temperature and maximum film-forming pressure using the amorphous macromolecular chain model; S108, determining the film forming time through a film forming experiment based on the maximum sublimation temperature, the maximum cracking temperature, the maximum film forming temperature, and the maximum film forming pressure; S109, constructing a sublimation rate calculation formula using the film forming time; S110, constructing a cracking rate calculation formula based on the maximum cracking temperature; S111, constructing a film forming rate calculation formula based on the maximum film forming temperature and the maximum film forming pressure; In step S110, the method for constructing a cracking rate calculation formula in combination with the maximum cracking temperature is: (1) The pre-exponential factor A of the cleavage reaction and the apparent activation energy E of the cleavage reaction are a Substituting into the Arrhenius equation, we get the equation for the cleavage rate constant: (2) the maximum cracking temperature T 裂解 Substitute into the cleavage rate constant equation to calculate the cleavage rate constant k1; (3) Determine the concentration of C-type parylene dimer, expressed as: c=P 成膜 / RT 裂解 Where, c is the molar concentration of C-type polyparaxylene dimer, mol / L; P 成膜 is the maximum film-forming pressure; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ; (4) Combined with the cleavage rate constant k1 and the concentration c of C-type polyparaxylene dimer, the cleavage rate of C-type polyparaxylene dimer is calculated: u 裂解 =ck1 Where, 裂解 is the cracking rate, mol / (Ls); c is the molar concentration of C-type p-xylene dimer, mol / L; k1 is the cracking rate constant, s -1 ; In step S111, a method for constructing a film forming rate calculation formula by combining the maximum film forming temperature and the maximum film forming pressure is as follows: (1) Change the free energy to Δ r G. Maximum film forming temperature T 成膜 And the maximum film forming pressure P 成膜 Substituting the following formula, we can obtain the rate constant k2 of C-type polyparaxylene dimer film formation: Where σ is the reaction path degeneracy, which is 1 for macromolecular systems; κ is the tunneling effect correction coefficient, which is 1; k b is the Boltzmann constant, 1.381×10 -23 J / K; h is Planck's constant, 6.62×10 -34 J·s; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ; Δ r G is the free energy change, kJ / mol; T 成膜 is the maximum film forming temperature, K; P 成膜 is the maximum film forming pressure, unit bar; N A is the number of molecules in 1 mol of a substance, 6.02×10 23 ; (2) Calculate the film forming rate: n 成膜 =ck2 Where, ν 成膜 is the film formation rate, mol / (L s); c is the molar concentration of C-type p-xylene dimer, mol / L; k2 is the rate constant k2 of C-type poly-p-xylene dimer film formation, s -1 .

2. The film forming rate matching method of C-type parylene dimer according to claim 1, characterized in that: In step S102, the sublimation temperature model of C-type parylene dimer is constructed and expressed as: Where, β i is the heating rate, K / min; T pi is the peak temperature of the DSC curve at different heating rates, K; T p0 is the temperature when the heating rate approaches 0, i.e. the maximum sublimation temperature, in K; b, c, and d are the sublimation temperature model coefficients.

3. The film forming rate matching method of C-type parylene dimer according to claim 2, characterized in that: The method for determining the maximum sublimation temperature in step S103 is: (1) Substituting the sublimation temperature peaks of the DSC curves at different heating rates into the sublimation temperature model to obtain a linear equation system; (2) Solve the linear equations to obtain the temperature T when the heating rate approaches 0 p0 , that is, the maximum sublimation temperature.

4. The film forming rate matching method of C-type parylene dimer according to claim 3, characterized in that: In step S104, the method for constructing the cracking temperature model of C-type parylene dimer is: (1) Use Gaussview to establish the model of C-type parylene dimer and monomer, and optimize the structure to minimize the energy; (2) The optimized C-type parylene dimer and monomer models were imported into Shermo software to calculate the free energy change Δ r G; (3) Change the free energy to Δ r Substitute G into the theoretical cracking rate equation to obtain the cracking temperature model, which is expressed as: Where, E a is the apparent activation energy of cracking, kJ / mol; k TST is the theoretically calculated fragmentation rate constant, s -1 ; R is the ideal gas constant, 8.314 J·mol -1 ·K -1 ; A is the pre-exponential factor of the cleavage reaction; T 裂解 is the maximum cracking temperature, K.

5. The film forming rate matching method of C-type parylene dimer according to claim 4, characterized in that: In step S105, the method for solving the maximum cracking temperature is: (1) The peak cracking temperature of the DTG curve at different heating rates was introduced into the Kissinger equation and the Ozawa equation, and the pre-exponential factor A of the cracking reaction and the apparent activation energy E of the cracking reaction were obtained through regression analysis. a ; (2) Calculate the cracking rate constant k by combining the gas decomposition rate equation under ideal conditions TST ; (3) Binding cleavage rate constant k TST , the pre-exponential factor A of the cleavage reaction and the apparent activation energy E of the cleavage reaction a , calculate the maximum cracking temperature T 裂解 .

6. The film forming rate matching method of C-type parylene dimer according to claim 5, characterized in that: In step S106, the method for constructing the amorphous macromolecular chain model of C-type parylene dimer is: (1) Construct a macromolecular model of C-type parylene dimer with a chain length of 100 to 1200 structural units and ensure that the macromolecular model has the lowest energy; (2) Inserting macromolecular models of C-type parylene dimers with different chain lengths into amorphous cells to construct an amorphous model of C-type parylene dimers; (3) Under different pressures, the amorphous model is structurally optimized by cellular compression so that the molecular density of the amorphous model reaches a required value; (4) Annealing the amorphous model after structural optimization to eventually form multiple amorphous macromolecular chain models.

7. The film forming rate matching method of C-type parylene dimer according to claim 6, characterized in that: In step S109, the sublimation rate calculation formula is expressed as: Where, 升华 is the sublimation rate, g / h; m 二聚体 is the mass of C-type parylene dimer, g; t is the film forming time, h.

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