阅读说明：本技术 一种采用极端顶点法针对均质低介微波基板配方设计方法 (Method for designing formula of homogeneous low-dielectric microwave substrate by adopting extreme vertex method ) 是由 金霞 李攀 郭晓光 张海涛 王丽婧 韩伏龙 贾倩倩 张立欣 鲁思如 于 2019-11-01 设计创作，主要内容包括：本发明公开了一种采用极端顶点法针对均质低介微波基板配方设计方法。根据基板的介电性能指标要求,确定基板的组成成分；采用极端顶点设计法对玻璃纤维、无机填料、聚四氟乙烯乳液三种组分进行优化；进行单因子实验优化添加剂的用量,最后利用等值线图和曲面图,使用响应变量优化器,得到实验区域内全部添加剂比例的拟合值。本方法解决了材料的配方设计,将连续型变量的实验次数减少至10次以内,实验成本可减少80%以上；通过使用响应曲面分析法,获得包含全部显著项在内的最佳参数组合,满足顾客提出的多种性能指标的需求；通过配方优化及加工过程控制,获得介电性能一致性良好的均质低介微波复合介质基板,为均质材料的连续生产奠定基础。(The invention discloses a formula design method for a homogeneous low-dielectric microwave substrate by adopting an extreme vertex method. Determining the composition of the substrate according to the dielectric performance index requirement of the substrate; optimizing three components of glass fiber, inorganic filler and polytetrafluoroethylene emulsion by adopting an extreme vertex design method; and optimizing the dosage of the additive by a single factor experiment, and finally obtaining the fitting value of all the additive proportions in the experiment area by using the contour map and the surface map and using a response variable optimizer. The method solves the problem of material formula design, reduces the experiment times of continuous variables to be within 10 times, and reduces the experiment cost by more than 80%; by using a response surface analysis method, the optimal parameter combination containing all significant items is obtained, and the requirements of various performance indexes provided by customers are met; the homogeneous low-dielectric microwave composite medium substrate with good dielectric property consistency is obtained by optimizing the formula and controlling the processing process, and a foundation is laid for continuous production of homogeneous materials.)

1. A method for designing a formula of a homogeneous low-dielectric microwave substrate by adopting an extreme vertex method is characterized by comprising the following steps of:

step one, according to the dielectric performance index requirement of a substrate, determining the components of a homogeneous low-dielectric microwave composite medium substrate to be glass fiber with the relative dielectric constant of 6.0-6.9, inorganic filler with the relative dielectric constant of 3.0-4.0, polytetrafluoroethylene emulsion with the relative dielectric constant of 2.1-2.3 and auxiliary additives;

step two, obtaining the component of each component through theoretical calculation, and determining the limit value of the upper and lower bounds of each component element in the formula;

thirdly, adopting an extreme vertex design method to carry out material mixing experimental design, and adopting the extreme vertex design method to optimize the formula combination of the glass fiber, the inorganic filler and the polytetrafluoroethylene emulsion;

step four, fitting the selected model, and performing residual error analysis;

judging whether each item effect of the model is significant or not until all the item effects in the model are significant;

observing the change trend in the whole range through the contour map and the surface map, and accurately calculating the optimal formula parameters of the significant factors by using a response variable optimizer;

step seven, carrying out a single-factor experiment, optimizing the dosage of the auxiliary additive, improving the processability in the material mixing process, being beneficial to obtaining homogeneous substrate materials in production and ensuring that the expected effect can be obtained by carrying out production according to the optimal conditions;

and step eight, verifying and curing the formula, carrying out continuous batch production, controlling the test value of the homogeneous low-dielectric microwave composite medium substrate, and monitoring by using a control chart to ensure the stability and controllability of the dielectric property.

Technical Field

The invention relates to a microwave dielectric substrate material, in particular to a formula design method for a homogeneous low-dielectric microwave composite substrate by adopting an extreme vertex method (extreme vertices design), and particularly relates to a control method for the dielectric property consistency of the homogeneous low-dielectric microwave composite substrate.

Background

With the rapid development of microwave communication technology, the requirements of terminal products such as 5G networks and automobile navigation on information transmission quality are higher and higher, and the traditional microwave dielectric substrate material is more and more difficult to meet the requirements of electronic products on light weight, high frequency and high speed of signal transmission and the like. PTFE resin is a high molecular material with an unbranched molecular structure which is completely symmetrical, and the specific structure ensures that the relative dielectric constant of the PTFE resin is 2.1 and the dielectric loss is 0.0001 under 1 MHz. The F atom having extremely high electronegativity makes the bond energy of C-F bond large, and the F atom has large volume and short distance of C-F bond, so that PTFE molecular chains are tightly bonded, and thus it has excellent chemical resistance and heat resistance and can be continuously used at high temperature. However, due to the factors of the PTFE resin such as softness, large thermal expansion coefficient, low strength, etc., inorganic fillers are required to be added for enhancing the performance. The low dielectric ceramic powder is widely used for microwave ceramic devices by virtue of dielectric and loss properties and relatively low temperature coefficient, and the PTFE/ceramic powder composite dielectric substrate prepared by adopting the low dielectric ceramic powder has the characteristics of capability of adjusting the relative dielectric constant of a product within a certain range, relatively low dielectric loss and the like. However, in the material mixing process, molecular chains of the PTFE resin are easy to orient under the action of shearing force and are difficult to be uniformly mixed with the low dielectric ceramic powder filler, and a lubricating agent is required to be added in the material mixing process, so that the shearing force of the PTFE resin is reduced, and the mixing uniformity of the PTFE resin and the filler is improved. However, in the mixed material formula research, the proportion of each component is a continuously adjustable parameter, and the step-by-step experiment for searching the optimal value obviously needs high experiment cost and is difficult to realize. Therefore, a scientific experimental design method is needed as a guide, and an effective theoretical model is obtained while the experimental cost is reduced and the experimental period is shortened, so that the goals of formula design and optimization are achieved.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and particularly provides a formula design method for a homogeneous low-dielectric microwave substrate by adopting an extreme vertex method, wherein the dielectric property of the substrate is stable and controllable through the formula design. The method adopts an extreme vertex design method combined with a response variable optimizer to design a formula. The extreme vertex design method is suitable for the field of limitation of upper and lower bounds of component components in mixed material design, and is a simple, convenient and effective design method. The intersection point of each limiting plane is called an extreme vertex, and a mixing experiment scheme formed by utilizing an extreme vertex set is called an extreme vertex design scheme. An extreme vertex design method is adopted, a full model is selected, then the whole change trend is observed according to an isoline and a surface graph, in order to accurately calculate the index setting of the dielectric property, a response variable optimizer is used to obtain a fitting theoretical model and a regression equation, a verification experiment is carried out, and the expected effect can be obtained by carrying out production according to the optimal formula condition.

The technical scheme adopted by the invention is as follows: a method for designing a formula of a homogeneous low-dielectric microwave substrate by adopting an extreme vertex method is characterized by comprising the following steps of:

step one, according to the dielectric performance index requirement of the substrate, determining the components of the homogeneous low-dielectric microwave composite medium substrate to be glass fiber with the relative dielectric constant of 6.0-6.9, inorganic filler with the relative dielectric constant of 3.0-4.0, polytetrafluoroethylene emulsion with the relative dielectric constant of 2.1-2.3 and auxiliary additives.

And step two, obtaining the component of each component through theoretical calculation, and determining the limit value of the upper and lower bounds of each component element in the formula.

And step three, adopting an extreme vertex design method to carry out material mixing experimental design, and adopting the extreme vertex design method to optimize the formula combination of the glass fiber, the inorganic filler and the polytetrafluoroethylene emulsion.

And step four, fitting the selected model, and performing residual analysis.

And fifthly, judging whether each item effect of the model is obvious or not until all the item effects in the model are obvious.

And step six, observing the change trend in the whole range through the contour map and the surface map, and accurately calculating the optimal formula parameters of the significant factors by using a response variable optimizer.

And seventhly, performing a single-factor experiment, optimizing the using amount of the auxiliary additive, improving the processability in the material mixing process, facilitating the obtaining of homogeneous substrate materials in production, and ensuring that the expected effect can be obtained by carrying out production according to the optimal conditions.

And step eight, verifying and curing the formula, carrying out continuous batch production, controlling the test value of the homogeneous low-dielectric microwave composite medium substrate, and monitoring by using a control chart to ensure the stability and controllability of the dielectric property.

The method comprises the steps of firstly determining the formula composition of the homogeneous low-dielectric microwave composite medium substrate according to customer index requirements and raw material performance, determining the limiting values of the upper and lower bounds of each component in the formula, creating a material mixing design, and selecting an extreme vertex method according to actual conditions. And secondly, performing an experiment according to an experimental scheme schedule, collecting data, observing the change trend in the whole range through a contour map and a surface map, and accurately calculating the optimal combination parameters of the significant factors by using a response variable optimizer to ensure that the expected effect can be obtained by performing production according to the optimal conditions. And finally, curing the formula, carrying out continuous batch production, controlling the consistency of the dielectric property of the substrate of the formula, and monitoring by using a control chart to ensure that the dielectric property of the substrate of the formula is stable and controllable.

The invention has the following beneficial effects: the method combines an extreme vertex design method and a response surface analysis method, solves the formulation design of homogeneous materials, can reduce the experiment times of continuous variables to be within 10 times by using the extreme vertex design method, and can reduce the experiment cost by more than 80%; by using a response surface analysis method, the optimal parameter combination containing all significant items can be obtained, and the requirements of various performance indexes provided by customers are met; the homogeneous low-dielectric microwave composite medium substrate with good dielectric property consistency is obtained by optimizing the formula and controlling the processing process, and a foundation is laid for continuous production of homogeneous materials.

The method provides a theoretical calculation tool and a theoretical calculation method for the continuous variable homogeneous material formula design, achieves the purpose of the formula design of the homogeneous low-dielectric microwave composite medium substrate material by utilizing an extreme vertex design method and a response surface analysis method, simultaneously improves the processability of the material processing process, solves the difficulties of huge experimental amount, high experimental cost and long experimental period in the heterogeneous composite material formula design, and simultaneously solves the bottleneck problem that the homogenization process is difficult to implement due to the characteristic difference of the heterogeneous material in the processing process of the homogeneous composite material.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a response tracking diagram of a compounding design according to an embodiment of the present invention;

FIG. 3 is a contour plot of compounding design response variables according to an embodiment of the present invention;

FIG. 4 is a surface plot of compounding design response variables according to an embodiment of the present invention;

FIG. 5 is a result diagram of a response variable optimizer of the compounding design according to the embodiment of the present invention;

FIG. 6 is a graph illustrating a single-value range control of dielectric properties of a mean substrate material according to an embodiment of the present invention.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

referring to fig. 1, a method for designing a formulation of a homogeneous low dielectric microwave substrate using an extreme vertex method includes the steps of:

the method comprises the following steps: the formula component elements of the homogeneous low-dielectric microwave composite medium substrate are determined to be glass fibers with the relative dielectric constant of 6.0-6.9, inorganic fillers with the relative dielectric constant of 3.0-4.0 and polytetrafluoroethylene emulsion with the relative dielectric constant of 2.1-2.3 according to the index requirements of customers and the performance of raw materials, and if the characteristics of the raw materials do not meet the range, the index requirements of the customers cannot be met.

Step two: and determining the limit values of the upper and lower bounds of each component element in the formula, namely 1-5 wt% of glass fiber, 35-69 wt% of inorganic filler and 30-60 wt% of polytetrafluoroethylene emulsion.

Step three: selecting a mixing design experiment tool according to actual conditions, and making a mixing experiment scheme schedule by using minitab software; according to the statistics in minitab software → DOE → mixing → mixed material design creation → extreme vertex method selection, after filling in the number of factors, the corresponding experimental scheme schedule can be obtained, as shown in Table 1.

Table 1 mixing design experiment schedule

Step four: experiments were performed and data were collected to obtain the relative permittivity results for each combination, as shown in table 2.

Table 2 mixing design experiment plan result table

Step five: using the mixing experiment analysis function in minitab software, from statistics → DOE → mixing → analysis of mixing design entrance, after deleting the item with the minimum effect, fitting the regression equation to obtain the following results, as shown in table 3.

TABLE 3 analysis of variance of regression coefficients of relative dielectric constant

According to the statistical principle, the P value is the probability of the occurrence of an alternative hypothesis when the original hypothesis is true, and the boundary line with the P value less than or equal to 0.05 is considered as the statistical significance. From the results in table 3, the main effect P value =0.001 <0.05, and the regression results were significant.

Step six: the effect of each individual factor can be shown by a response tracker (as shown in fig. 2), the trend of the change in the whole range is observed by a contour map (as shown in fig. 3) and a surface map (as shown in fig. 4), and the optimal formulation parameters for obtaining the significant factor are accurately found by a response variable optimizer (as shown in fig. 5) to be glass fiber (2.95 wt%), inorganic filler (52.89 wt%) and polytetrafluoroethylene emulsion (44.16 wt%), and the formulation conditions meet the requirement of a customer that the relative dielectric constant reaches 2.94.

Step seven: in order to improve the processability of the composite material, additives are required to be used in the processing process, according to the processing characteristics and the using place of the composite material in the embodiment, the additives are formed by combining liquid paraffin, dipropylene glycol, petroleum ether and aviation kerosene according to a certain proportion, single-factor experiments are carried out according to the using amount of the additives, the experiment plan and the results are shown in table 4, the single-factor experiments with the specific gravity (wt%) of the additives of 5%, 7%, 9%, 11%, 13% and 15% are respectively carried out, the using amount of the additives is determined to be 13wt% according to the result of the relative dielectric constant uniformity, and the processing performance is ensured to meet the customer requirement that the relative dielectric constant uniformity is less than 0.05.

TABLE 4 additive Single factor Experimental plan and results

Step eight: curing the formula, carrying out continuous batch production, controlling the dielectric property of the substrate of the formula, monitoring by using a control chart, as shown in figure 6, ensuring that the dielectric property of the substrate of the formula is stable and controllable, and no alarm occurs in the control chart, and obtaining the consistency index of the relative dielectric constant of 30 batches of substrates which are continuously produced in batches, wherein the consistency index is 0.0036 and less than 0.05 (the consistency index is less than 0.05 and is required by customers), and the effect is good.

The embodiment shows that the method combines the pole tip design method and the response surface analysis method, solves the formulation design and optimization of the homogeneous material, can reduce the experiment times of continuous variables by 9 times and reduce the experiment cost by more than 80 percent by using the pole tip design method; by using a response surface analysis method, the optimal parameter combination containing all significant items can be obtained to be glass fiber (2.95 wt%), inorganic filler (52.89 wt%) and polytetrafluoroethylene emulsion (44.16 wt%), and the requirement of customers on the relative dielectric constant reaching 2.94 +/-0.04 at the present stage can be met under the formula condition; meanwhile, the formula requirements meeting other different relative dielectric constant indexes proposed by customers can be obtained through the simulation result of the response optimizer. Six experiments are carried out to obtain the optimization result of the additive content, the processing performance of the composite material is further improved, continuous production is carried out under the condition that the using amount of the additive is 13wt%, a homogeneous low-dielectric microwave composite medium substrate with good dielectric property consistency is obtained, and a foundation is laid for the continuous production of the homogeneous material.