各向异性导电胶研究进展

随着微电子产业的不断发展,电子产品微型化和集成化趋势日益显著,新型电子封装材料也呈快速发展态势,其中各向异性导电胶(ACA)已成为新一代封装材料的主流。对近年来ACA的研究进展进行了综述,并对其今后的发展方向作了展望。     

双马改性环氧树脂导电胶粘剂的研究

在环氧树脂———胺类潜性固化———促进剂及Ag粉体系中添加双马树脂 ,可制成单组份 15 0℃固化 ,耐热性优良的导电胶粘剂。     

石墨/环氧树脂导电胶的研究

研究了以石墨、环氧树脂、三乙醇胺及其它添加剂组成的导电胶体系。分别以鳞片石墨、还原石墨、鳞片石墨/铝粉作导电介质制备石墨导电胶。通过多种分析手段对三种石墨导电胶的导电性能、力学性能和热学性能等进行了考察三种石墨导电胶的性能参数为:当w(石墨)=35份时,鳞片石墨导电胶鳞片石墨/铝粉导电胶和还原石墨导电胶的体积电阻率分别为0.05690.48830.2794Ω·cm,剪切强度分别为6.211.19.3MPa,热失重速率分别为-8.7-4.7-7%/min[当w(石墨)=30份、升温速率为8℃/min时]。石墨导电胶具有良好的工业应用前景。     

Predicting the damage development in epoxy resins using an anisotropic damage model

For fiber-reinforced plastics, the strain-rate dependent response is governed by the matrix behavior. In this work, the Goldberg model is considered for the epoxy matrix constitutive material model. Moreover, the strain-rate dependency is achieved by direct influence on the elastic modulus, the inelastic strain, and the material strain to failure. In addition, an anisotropic damage response is implemented and extended through a strain-rate dependent definition. Since the constitutive model relies on nonphysical parameters, a parameter study is further performed. Additional numerical investigations using a micro-mechanical model are performed. Tension and shear loading conditions are evaluated and the influence of different strain rates is explored. Furthermore, the implemented anisotropic damage model is compared and discussed against an isotropic damage model.     

Fast-curing adhesive compositions based on modified epoxy resins

The properties of two new fast-curing adhesive materials based on modified cold-curing epoxy resins are studied. The studied materials are used for the repair and production of complex technological equipment. The properties of fast-curing adhesives developed in Germany and Russia (OAO Kompozit) are compared, and it is shown that the strength properties of new adhesive materials are not inferior to foreign analogs and are distinguished by a high curing rate at room temperature; they display good service properties at high temperatures and enhanced humidity. The fields of application of the adhesives for bonding parts made of aluminum alloys and glass-and carbon-reinforced plastics are indicated.     

Thermal and hygroscopic reliability of flip-chip packages with an anisotropic conductive film

Thermal and hygroscopic reliability of anisotropic conductive film (ACF) joints in relation to flip-chip bonding force was evaluated by thermal shock and constant temperature/humidity testing. The failure mode by thermal shock testing varied with increasing bonding force, i.e., (1) formation of a conduction gap between conductive particles and Au bump or Ni/Au plated Cu pad at low bonding force and (2) delamination of adhesive matrix from the plated Cu pad on the flexible substrate at high bonding force. The delamination initiated as a crack under a conductive particle and propagated sideward resulting in a complete delamination of the ACF from the Cu pad. However, delamination was observed between the ACF and Au bump on the chip side after the constant temperature/humidity testing for 500 h. A theoretical calculation was also conducted to predict the connection resistance of the ACF joint before and after reliability tests. The calculation showed the importance of the bonding gap between the electrodes.     

水性环氧树脂的干燥及成膜

水性环氧树脂的成膜过程包括水分的挥发及树脂的交联固化,对其历程的深入了解及有效的控制,将直接影响着最终胶膜的结构及综合性能,本文侧重对其进行扼要的理性分析及介绍.     

Tannin-based adhesive cross-linked by furfuryl alcohol-glyoxal and epoxy resins

To prepare a natural tannin-based adhesive with good water resistance, an environment friendly furfuryl alcohol-glyoxal resin (FG) synthesized in the laboratory was developed as a cross-linker for tannin-based adhesives. ¹³C Nuclear Magnetic Resonance (NMR) and Matrix-Assisted Laser Desorption-Ionization Time-of-Flight (MALDI-TOF) mass spectroscopy results indicated that furfuryl alcohol and glyoxal reacted under acidic conditions and that the -CH-(OH)- groups could be shown to be the ones involved in the cross-linking of the tannin-furfuryl-glyoxal adhesive (TFG). The results for the wet shear strength of TFG-bonded plywood showed that the cured TFG was improved and better than that bonded with a tannin-furfuryl alcohol (TF) adhesive. Moreover, the TFG adhesive cross-linked with 12% epoxy resin (EPR) presented a good water resistance. It had a modulus of elasticity (MOE) higher than that of tannin-furfuryl alcohol-formaldehyde (TFF), TF and phenol-formaldehyde (PF) adhesives.     

Effect of cobalt on the electrical conductive property of epoxy resins

Cobalt acrylate (CoA₂) has been treated with bisphenol‐A and epichlorohydrin to modify epoxy resins. It was cured with p‐acetylbenzilidene triphenyl arsonium ylide. The properties such as epoxide equivalent weight (equiv/100 g), molecular weight, hydrolyzable chlorine content increases whereas hydroxyl content, refractive index decreases in the presence of CoA₂. The cured epoxy resins shows improve electrical conductivity due to the incorporation of CoA₂ with epoxy resins. The influence of complex formation of CoA₂ with either linkage of epoxy resins were investigated by spectroscopy. The decrease in T_g from differential scanning calorimetry support the improve in flexibility. The dispersion of cobalt in epoxy resins matrix was confirmed by scanning electron microscope. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

State-of-the-art production of epoxy resins and adhesive hardeners in Russia

The commercial production of epoxy resin ED-20 is discussed as this resin is the most important component in the formulations of adhesives and sealants in the Russian Federation. Classification of amine hardeners is presented, and basic trade marks of ethylene amines, modified amines, oligoaminoamide and imidazoline hardeners are listed, and their major characteristics are described.     

Toughening mechanisms of rubber modified thin film epoxy resins

An epoxy terminated polybutadiene (ETPB) was synthesized and utilized to enhance the toughening of an epoxy system, in both bulk and coating states. In the first step, the fracture energy of the modified samples was determined using a single edge notched type specimen in a three point bending (SEN3PB) geometry. The effective toughening mechanisms of bulk epoxy specimens were examined using scanning electron microscopy (SEM). The results showed that plastic void growth, cavitation and shear yielding mechanisms were the main toughening mechanisms of the bulk epoxy systems. In the next step, mechanical properties (i.e. impact resistance, flexibility, cupping resistance and hardness) and adhesion of the thin film specimens were evaluated in accordance to the amount of synthesized ETPB. The results showed that the mechanical properties of the ETPB modified epoxy resins considerably improved. In all cases, it was found that the improvement of the mechanical properties reached a maximum at 7.5 wt.% and then began to decrease with further increase in ETPB content. The effective toughening mechanisms in the modified thin films were also examined using SEM and compared to the bulk types. In contrast to the bulk types, the results showed that crack arresting and shear yielding were active mechanisms in thin films. The contribution of these mechanisms led to the improvement of adhesion and mechanical properties by energy dissipation.     

氯化丁基橡胶基阻尼导热胶的研制

以氯化丁基橡胶(CIIR)为主要基体、氢化松香(GA-85H)为阻尼赋予剂和氧化铝(Al_2O_3)为导热填料,制备CIIR基阻尼导热胶。研究结果表明:w(氢化松香)=150%(相对于CIIR质量而言)时,导热胶的阻尼性能和粘接性能相对最好;同时,在上述体系中,当m(总Al_2O_3)=200 g、m(5μm Al_2O_3)∶m(15μm Al_2O_3)=1∶3时,导热胶的综合性能相对最佳,其导热系数[0.73 W/(m·K)]相对最大。     

环氧基苯基硅油改性环氧树脂绝缘胶的研究

采用环氧基苯基硅油(PEPDMS)作为环氧树脂绝缘胶的增韧增柔改性剂。研究了PEPDMS对环氧树脂相容性、机械性能、耐热性和电性能的影响。实验结果表明,PEPDMS与环氧树脂具有良好的相容性,对环氧树脂具有显著的增强增韧的效果,且对环氧树脂的耐热性能和电性能无不良影响。但PEPDMS的加入使环氧树脂的玻璃化转变温度(T_g)略有下降。     

Structure and adhesive properties of epoxy resins modified with acrylic particles

The morphology and physical properties of dicyandiamide (DICY)-cured epoxy resin modified with acrylic particles were studied. We used one homopolymer of methyl methacrylate (MMA) and three copolymers of MMA and glycidyl methacrylate (GMA) [P(MMA-GMA)] containing different amounts of GMA as the acrylic particles. When a mixture of the acrylic particles and the epoxy resin was heated, the particles were swollen with the epoxy resin and thus a soft gel with no fluidity was formed. Further heating to the reaction temperature of the DICY cured the soft gel. The structure of the acrylic particles strongly affected the physical properties of the soft gel and the cured epoxy resin. The cured system containing 5 mol% of GMA showed the best physical properties (impact strength and adhesive property), but there was a tendency for the physical properties to decline with a higher GMA content. We have determined that the GMA content of the acrylic particles affects the concentration of network chains in the system.     

一种先进雷达天线罩粘接用胶膜的研制

采用高纯EP(环氧树脂)和热塑性树脂(Px)协同改性CE(氰酸酯)树脂,制备出一种新型的先进雷达天线罩粘接用胶膜。研究结果表明:该胶膜具有良好的自黏性,并且能够满足250℃时的使用要求;该胶膜经200℃固化4 d后,其室温储存期大于20 d,250℃剪切强度大于10 MPa,并且具有良好的韧性[滚筒剥离强度超过40(N·mm)/mm]和介电性能(介电常数为3.09、介电损耗为0.01),完全能够满足先进雷达天线罩结构的粘接要求。     

Basic analytical control techniques for epoxy resins and adhesive curing agents

Procedures for determination of basic quality characteristics of epoxide-bisphenol A resins and amine hardeners: the epoxide equivalent and the amine value, respectively; the viscosity; and the pot life are reported. A rapid method for the assessment of the gelation time of a mixture of an epoxy resin with a hardener is described.     

银包铜粉环氧导电胶的制备、结构与性能

为了研制性能优良的导电胶,选用双酚A型环氧树脂作为基体、四乙烯五胺作为固化剂、银包铜粉为导电填料、AA-75作为分散剂,制备了银包铜粉导电胶。使用直流低电阻测试仪测定了导电胶的体积电阻率;用红外光谱对添加不同量固化剂的导电胶进行了分析,用差示扫描量热仪对加入固化剂后的固化反应情况进行了测试。在最佳配比和最佳工艺条件下所制备的导电胶的体积电阻率达到8．9×10^-4Ω·cm。     

硅改性BPA-PA酚醛环氧树脂导电胶的合成及性能

以双酚A多聚甲醛酚醛树脂（BPA-PA酚醛树脂）、二甲基二甲氧基硅烷和环氧氯丙烷为原料,通过酯交换反应和亲核取代反应得到硅改性BPA-PA酚醛环氧树脂。采用傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）分析进行结构确证。结合非等温DSC、T-β外推直线和FTIR分析研究了最佳固化工艺条件。探讨了不同硅烷添加量对硅改性BPA-PA酚醛环氧树脂性能的影响。最后以硅改性BPA-PA酚醛环氧树脂为基体树脂,加以导电填料和助剂,制备出中温型导电胶。对导电胶进行拉伸剪切强度、体积电阻率和热重测试分析,结果显示：自制硅改性BPA-PA酚醛环氧树脂导电胶拉伸剪切强度达到20.18MPa、体积电阻率达到7.44×10^-4Ω·cm,残炭量达到68.89%。相对市售E-51环氧树脂所制导电胶,自制硅改性BPA-PA酚醛环氧树脂导电胶拉伸剪切强度提高5.73MPa,体积电阻率降低3.86×10^-4Ω·cm,残炭量提高7.49%。