Mechanical Properties of Electronic Interconnected Conductive Adhesive and Drop Impact Behavior of Adhesive Bonding Point
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摘要: 电子互连导电胶在便携式电子产品中具有广泛的应用前景，其在服役过程中常承受跌落冲击工况，导致微小导电胶互连点处产生相对较高的应变率，因此关于导电胶在较高应变率下的力学行为及胶连点跌落可靠性研究显得尤为重要。以环氧树脂基添加银导电颗粒各向同性导电胶（ICA）为研究对象，采用万能试验机和分离式霍普金森压杆装置对其开展不同应变率下的力学性能研究，在此基础上进行导电胶互连封装结构的跌落冲击数值模拟分析。结果表明：固化导电胶在动态时具有明显的应变率效应；跌落冲击时，关键胶连点出现在4个边角处且小角度跌落比水平跌落更危险；两种跌落方式中，基座长边跌落方式在关键胶连点处产生的应力、应变相对较大。Abstract: Electronic interconnected conductive adhesive has a wide range of application prospects in portable electronic products. It is often subjected to drop impact conditions during service, resulting in a relatively high strain rate at the bonding point of tiny conductive adhesive. Therefore, the research on the mechanical behavior of conductive adhesive under a higher strain rate and the drop reliability of bonding point is particularly important. Herein, the rate-dependent properties of the epoxy resin-based isotropic conductive adhesive (ICA) with silver conductive particles were investigated by using the universal testing machine and the split Hopkinson pressure bar. Furthermore, the numerical simulation analysis of the conductive adhesive interconnection package structure under drop impact was carried out. The dynamic results show that the cured ICA is sensitive to strain rate. It is clear that the key bonding point appears at the four corners, and the small-angle drop is more dangerous than that of the horizontal drop. The long-side drop mode results in a relatively large stress and strain at the key bonding point in comparison with that of the short-side drop mode.
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Key words:
- conductive adhesive /
- mechanical properties /
- strain rate /
- drop impact
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图 2 各向同性固化导电胶的准静态(a)和动态(b)真应力-应变曲线
Figure 2. Quasi-static (a) and dynamic (b) true stress-strain curves of cured ICA
图 7 不同跌落角度下的最大等效应力(a)和最大等效塑性应变(b)
Figure 7. The maximum Mises stress (a) and maximum PEEQ (b) at different drop angles
图 8 不同跌落高度下的最大等效应力(a)和最大等效塑性应变(b)
Figure 8. The maximum Mises stress (a) and maximum PEEQ (b) at different drop heights
表 1 不同应变率下固化导电胶的动态屈服强度
Table 1. Dynamic yield strength of cured ICA at different strain rates
Test No. Strain rate/s−1 Yield strength/MPa 1 1100 184.6 2 2100 215.8 3 3200 238.0 
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表 2 基板和PCB板的横观各向同性参数
Table 2. Transversely isotropic parameters of substrate and PCB board
Component Ex，Ey/GPa Ez/GPa Gxz，Gyz/GPa Gxy/GPa $\gamma$xz，$\gamma$yz $\gamma$xy $\,\rho $/(kg·m−3) Substrate 16.8 7.4 7.59 3.31 0.39 0.11 1910 PCB 17.7 7.8 7.99 3.49 0.39 0.11 1910
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表 3 各材料的力学参数
Table 3. Mechanical parameters of materials
Material E/GPa $\gamma$ $\,\rho $/(kg·m−3) Bolt 206 0.28 7800 Chip 131 0.23 2330 Cu 117 0.38 8960 Resin 28 0.35 1890 Base 200 0.27 7800 Impact platform 20 0.20 2400
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表 4 ICA的力学参数
Table 4. Mechanical parameters of cured ICA
Material E/GPa $\gamma$ $\,\rho $/(kg·m−3) C/s−1 P ICA 1.63 0.4 4050 3641 1.3
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表 5 不同跌落工况下的
$\textit{z}$ 向最大应力Table 5. Maximum
$\textit{z}$ -axis stress under different drop conditionsHeight/m $\sigma $0/MPa $\sigma $1/MPa $\sigma $2/MPa Height/m Drop angle/(°) $\sigma $11/MPa $\sigma $12/MPa 1.0 150.1 148.2 −290.9 1.0 10 −193.6 −145.3 1.2 158.3 −175.2 −263.1 1.0 15 −155.9 −181.4 1.5 173.1 188.7 −270.0 1.0 20 92.5 −232.8 1.8 185.9 −194.4 −320.3 1.0 25 97.6 −146.0 2.0 193.5 196.2 −323.9 1.0 30 101.2 −132.4
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[1] TUNTHAWIROON P, KANLAYASIRI K. Effects of Ag contents in Sn-xAg lead-free solders on microstructure, corrosion behavior and interfacial reaction with Cu substrate [J]. Transactions of Nonferrous Metals Society of China, 2019, 29(8): 1696–1704. doi: 10.1016/S1003-6326(19)65076-4 [2] ZHANG S Y, QI X Q, YANG M, et al. A study on the resistivity and mechanical properties of modified nano-Ag coated Cu particles in electrically conductive adhesives [J]. Journal of Materials Science: Materials in Electronics, 2019, 30(10): 9171–9183. doi: 10.1007/s10854-019-01246-8 [3] ZHANG L, SU Y, DAI Y Q, et al. Effect of the silver with different morphologies on the performance of electrically conductive adhesives [J]. Rare Metal Materials and Engineering, 2020, 49(5): 1526–1532. [4] 张小敏, 李起龙, 杜海涛, 等. 镀银铜粉导电胶制备及表征 [J]. 高校化学工程学报, 2020, 34(4): 1069–1075. doi: 10.3969/j.issn.1003-9015.2020.04.029ZHANG X M, LI Q L, DU H T, et al. Preparation and characterization of ultrafine silver-coated copper powder and electrical conductive adhesives [J]. Journal of Chemical Engineering of Chinese Universities, 2020, 34(4): 1069–1075. doi: 10.3969/j.issn.1003-9015.2020.04.029 [5] ARADHANA R, MOHANTY S, NAYAK S K. A review on epoxy-based electrically conductive adhesives [J]. International Journal of Adhesion and Adhesives, 2020, 99: 102596. doi: 10.1016/j.ijadhadh.2020.102596 [6] WU M L, LAN J S. Reliability and failure analysis of SAC 105 and SAC 1205N lead-free solder alloys during drop test events [J]. Microelectronics Reliability, 2018, 80: 213–222. doi: 10.1016/j.microrel.2017.12.013 [7] WANG X Q, GAN W P, GE T T, et al. Effect of tetraethylenepentamine on silver conductive adhesive [J]. JOM, 2018, 70(9): 1800–1804. doi: 10.1007/s11837-018-2939-4 [8] ZHAN H J, GUO J Y, YANG X Z, et al. Silver frameworks based on self-sintering silver micro-flakes and its application in low temperature curing conductive pastes [J]. Journal of Materials Science: Materials in Electronics, 2019, 30(24): 21343–21354. doi: 10.1007/s10854-019-02511-6 [9] SU Y, ZHANG L, LIAO B, et al. Simultaneous improvement of the electrical conductivity and mechanical properties via double-bond introduction in the electrically conductive adhesives [J]. Journal of Materials Science: Materials in Electronics, 2020, 31(11): 8923–8932. doi: 10.1007/s10854-020-03427-2 [10] SPRINGER M, BOSCO N. Linear viscoelastic characterization of electrically conductive adhesives used as interconnect in photovoltaic modules [J]. Progress in Photovoltaics: Research and Applications, 2020, 28(7): 659–681. doi: 10.1002/pip.3257 [11] 杨雪霞, 肖革胜, 树学峰. 板级跌落冲击载荷下无铅焊点形状对BGA封装可靠性的影响 [J]. 振动与冲击, 2013, 32(1): 104–107. doi: 10.3969/j.issn.1000-3835.2013.01.022YANG X X, XIAO G S, SHU X F. Effects of solder joint shapes on reliability of BGA packages under board level drop impact loads [J]. Journal of Vibration and Shock, 2013, 32(1): 104–107. doi: 10.3969/j.issn.1000-3835.2013.01.022 [12] TAN A T, TAN A W, YUSOF F. Influence of high-power-low-frequency ultrasonic vibration time on the microstructure and mechanical properties of lead-free solder joints [J]. Journal of Materials Processing Technology, 2016, 238: 8–14. doi: 10.1016/j.jmatprotec.2016.06.036 [13] HE X, YAO Y. A dislocation density based viscoplastic constitutive model for lead free solder under drop impact [J]. International Journal of Solids and Structures, 2017, 120: 236–244. doi: 10.1016/j.ijsolstr.2017.05.005 [14] LONG X, XU J M, WANG S B, et al. Understanding the impact response of lead-free solder at high strain rates [J]. International Journal of Mechanical Sciences, 2020, 172: 105416. doi: 10.1016/j.ijmecsci.2020.105416 [15] 余同希, 邱信明. 冲击动力学 [M]. 北京: 清华大学出版社, 2011. [16] PARK R. State of the art report ductility evaluation from laboratory and analytical testing [C]//Proceedings of Ninth World Conference on Earthquake Engineering. Tokyo, 1988: 605−616. [17] JEDEL Solid State Technology Association. JESD22-B111 board level drop test method of components for handheld electronic products [S]. Arlington: JEDEL Solid State Technology Association, 2003. [18] 樊泽瑞. POP封装板级跌落可靠性研究 [D]. 广州: 华南理工大学, 2012.FAN Z R. Research on reliability of board level package-on-package in drop impact [D]. Guangzhou: South China University of Technology, 2012. [19] LAI Y S, YANG P C, YEH C L. Effects of different drop test conditions on board-level reliability of chip-scale packages [J]. Microelectronics Reliability, 2008, 48(2): 274–281. doi: 10.1016/j.microrel.2007.03.005 [20] 吉新阔, 肖革胜, 刘二强, 等. 高温下不同银含量微电子胶连点的力学性能及膨胀系数不匹配热应力 [J]. 复合材料学报, 2017, 34(11): 2455–2462. doi: 10.13801/j.cnki.fhclxb.20170308.002JI X K, XIAO G S, LIU E Q, et al. High-temperature mechanical properties and thermal mismatch stress of conductive adhesive with different silver contents in flip chip packaging [J]. Acta Materiae Compositae Sinica, 2017, 34(11): 2455–2462. doi: 10.13801/j.cnki.fhclxb.20170308.002 -
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