环氧树脂灌封结构固化行为数值模拟和工艺优化

李小阳; 康峻铭; 朱子钊; 杨鹏; 王继辉; 丁安心

doi:10.13801/j.cnki.fhclxb.20200922.001

环氧树脂灌封结构固化行为数值模拟和工艺优化

doi: 10.13801/j.cnki.fhclxb.20200922.001

1.
中国工程物理研究院　电子工程研究所，绵阳 621900
2.
武汉理工大学　材料科学与工程学院，武汉 430070

基金项目: 国家自然科学基金(11902231)；中央高校基本科研业务费专项资金(WUT203201006；WUT203101002)

详细信息

通讯作者:
丁安心，博士，教授，研究方向为聚合物和聚合物基复合材料制备与设计　E-mail：axding@whut.edu.cn

中图分类号: TB334
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- 被引次数: 0
出版历程
- 收稿日期: 2020-07-20
- 修回日期: 2020-08-24
- 录用日期: 2020-08-29
- 网络出版日期: 2020-09-22
- 刊出日期: 2021-09-01

Numerical simulation on cure behavior and optimization on cure cycle for encapsulation structure of epoxy resin

1.
Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621900, China
2.
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China

摘要

摘要: 依据实验测试获得E51环氧树脂的固化动力学和力学性能参数，针对特定尺寸的E51树脂灌封结构，将数值模拟与实验方法相结合，优化树脂的常温固化工艺为“二阶段”中高温固化工艺。首先采用数值模拟方法，分别比较第一段保温平台和第二段保温平台不同温度幅值和固化时间对结构内部的温度、固化度和应变的影响，优选固化工艺参数；然后基于光纤布拉格光栅(FBG)监测技术，对优选和原始固化工艺曲线的结构内部的固化温度和应变进行实时在线监测，结果表明了数值模拟的可行性，显示了通过数值仿真优选固化工艺曲线的可靠性；最后实验测试比较优选工艺和原始工艺曲线下制造的E51树脂浇注体性能，结果显示优选工艺制造的树脂浇注体的拉伸强度、压缩屈服强度、弯曲强度和冲击强度相比原始工艺制作的试样分别提高了3.9%、1.5%、14.5%和16.2%。
- 固化应力 /
- 数值模拟 /
- 灌封结构 /
- 固化工艺 /
- 固化 /
- 环氧树脂 /
- 光纤布拉格光栅
Abstract: This paper aims at optimizing the cure cycle of specific encapsulation structures composed of E51 resin from room temperature cure cycle to medium-high “two-phase” cure cycle by means of combination of numerical simulation and experimental testing on the basis of experimentally obtained parameters of cure kinetics and mechanical properties for E51 epoxy resin. The numerical method was firstly adopted to simulate the effects of temperature magnitude and curing time in the first and second dwelling phase to internal temperature, degree of cure and strain of structure during curing to optimize the process parameter. Then the internal temperature and strain of the structure were real-time recorded using Fiber Bragg Grating (FBG) monitoring technique, and the corresponding results reveal the validity of numerical simulation, which demonstrates the reliability of the approach of optimizing the cure cycle using numerical simulation. Lastly, the properties of the casting body specimens of E51 resin manufactured with optimized and original cure cycle were compared, and the results show that the tensile strength, compressive yield strength, flexural strength and impact strength for the specimens manufactured with optimized cure cycle increase by 3.9%, 1.5%, 14.5% and 16.2% compared with the specimens manufactured with original cure cycle, respectively.
- cure-induced stress /
- numerical simulation /
- encapsulation structures /
- cure cycle /
- cure /
- epoxy resin /
- Fiber Bragg Grating (FBG)

HTML全文

图 1 E51树脂灌封结构的有限元模型

Figure 1. Finite element model of encapsulation structure composed of E51 resin

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图 2 E51树脂的固化工艺曲线优化流程图

Figure 2. Flowchart of optimization on cure cycle for E51 resin

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图 3 在不同固化工艺下(第一段30℃/40℃/50℃-24 h+第二段70℃-6 h)E51结构监测点的相关参数变化：(a) 温度；(b) 固化度；(c) 应变

Figure 3. Evolution of pertinent parameters in the monitored position for structures composed of E51 resin under different cure cycles (30℃/40℃/50℃-24 h in the first dwelling stage +70℃-6 h in the second dwelling stage): (a) Temperature; (b) Degree of cure; (c) Strain

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图 4 在不同固化工艺下(第一段30℃-3/6/12/24 h+第二段70℃-6 h)E51结构监测点的相关参数变化：(a) 温度；(b) 固化度；(c) 应变

Figure 4. Evolution of pertinent parameters in the monitored position for structures composed of E51 resin under different cure cycles ( 30℃-3/6/12/24 h in the first dwelling stage +70℃-6 h in the second dwelling stage) : (a) Temperature; (b) Degree of cure; (c) Strain

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图 5 在不同固化工艺下(第一段30℃-24 h+第二段50/60/70/80℃-6 h)E51结构监测点的相关参数变化：(a) 温度；(b) 固化度；(c) 应变

Figure 5. Evolution of pertinent parameters in the monitored position for structures composed of E51 resin under different cure cycles ( 30℃-24 h in the first dwelling stage +50/60/70/80℃-6 h in the second dwelling stage): (a) Temperature; (b) Degree of cure; (c) Strain

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图 6 在不同固化工艺下(第一段30℃-24 h+第二段70℃-2/3/4/5/6 h)E51结构监测点的相关参数变化：(a) 温度；(b) 固化度；(c) 应变

Figure 6. Evolution of pertinent parameters in the monitored position for structures composed of E51 resin under different cure cycles ( 30℃-24 h in the first dwelling stage +70℃-2/3/4/5/6 h in the second dwelling stage): (a) Temperature; (b) Degree of cure; (c) Strain

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图 7 E51树脂结构监测点在原始固化工艺下的实验曲线和模拟曲线

Figure 7. Experimentally measured and numerically simulated strain and temperature curves for monitored point of structures composed of E51 resin under original cure cycle

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图 8 E51树脂结构监测点在原始固化工艺下的实验曲线和模拟曲线

Figure 8. Experimentally measured and numerically simulated strain and temperature curves for monitored point of structures composed of E51 resin under optimized cure cycle ((a) Experimental results; (b) Temperature comparison between experimental and numerical results; (c) Strain comparison between experimental and numerical results)

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图 9 固化工艺优化前后的E51树脂浇注体性能对比：(a)拉升强度和压缩强度；(b)弯曲强度和冲击强度

Figure 9. Comparison of properties for E51 resin casting body manufactured with optimized and original cure cycles: (a) Tensile and compressive yield strength; (b) Flexural strength and impact strength

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表 1 E51树脂固化动力学和热物理性能参数

Table 1. Parameters for the curing kinetic model and thermophysical properties of E51 resin

Parameter	Value
A₁/ S⁻¹	9.64×10⁶
A₂/ S⁻¹	1.36×10³
ΔE₁/(J·mol⁻¹)	6.69×10⁴
ΔE₂/(J·mol⁻¹)	4.12×10⁴
m	0.3
n	1.7
D	50
α_c0	−2.40
α_cT	0.01
ΔH/(J·g⁻¹)	402.7
ρ₀/(kg·m⁻³)	1108.9
ρ₁/(kg·m⁻³)	1168.7
k₀/(W·(m·K)⁻¹)	0.16
k₁/(W·(m·K)⁻¹)	0.22
C_p0/(J·(kg·K)⁻¹)	1763
C_p1/(J·(kg·K)⁻¹)	1171
Notes: A₁ and A₂—Pre-exponential factors; ΔE₁ and ΔE₂—Activation energies; m and n—Exponential constants; D—Diffusion factor; α_c0 and α_cT—Fitting parameters; ΔH—Total heat quantity of heat release after the resin is fully cured; ρ₀ and ρ₁—Densities of completely uncured and cured resin; k₀ and k₁—Thermal conductivities of completely uncured and cured resin; C_p0 and C_p1—Specific heat capacities of completely uncured and cured resin.

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表 2 E51树脂固化力学性能参数

Table 2. Parameters for the curing mechanical properties of E51 resin

Parameter	Value
T_g0/℃	−47.78
T_g1/℃	84.03
l	0.49
α	0.48
T₁/K	−5
T₂/K	5
T₃/K	15
T₄/K	50
G₁/Pa	1.35×10⁶
G₂/Pa	4.25×10⁸
G₃/Pa	7.65×10⁸
G₄/Pa	1.045×10⁹
E_che	2.0×10⁻³
E_the/K⁻¹	32.0×10⁻⁶
Notes: T_g0 and T_g1—Glass transition temperatures of completely uncured and cured resin; l—Fitting parameter; α—Degree of cure; T₁, T₂, T₃ and T₄—Fitting values of temperature; G₁, G₂, G₃ and G₄—Fitting values of shear moduli; E_che and E_the — Coefficients of chemical shrinkage and thermal expansion.

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