快速固化环氧胶用聚酰胺固化剂的合成及性能

采用熔融缩聚法合成新型聚酰胺,以二乙烯三胺、三乙烯四胺、二酸为原料制备聚酰胺,并对聚合产物结构进行了红外表征。讨论了反应温度、反应时间、原料配比对产物性能的影响,研究环氧树脂固化剂的最佳制备工艺,最后将文章合成的聚酰胺固化剂与二氨基二苯砜配制成复合固化剂。重点讨论复合固化剂的最佳配比及使用复合固化剂制备胶粘剂时,其最佳固化剂配比,通过实验方法确定胶膜在(150-170)℃下,10min内可完全固化。结果表明:当酸胺的物质量的配比为1:2时,酰胺化反应在180℃反应2h,所得固化剂的性能最好;复合固化剂4,4’一二氨基二苯砜(DDS):聚酰胺(PA)最佳配比为1:5时,环氧树脂与复合固化剂的质量比为10:1时,制备的环氧快速固化包封膜在(150-170)℃下,10min固化条件下,剥离强度为1.35N/mm,性能优良。制备的快速固化环氧包封膜固化速度快,综合性能良好,具有较高的剥离强度、合适的溢胶量、良好的耐焊性和耐酸碱性能,满足FPC生产的要求。     

聚苯醚改性环氧树脂基覆铜板的研制

利用浊点绘制了聚苯醚与溴化环氧树脂体系的相图，通过对相图的分析研究了体系的相容性；讨论了胶液的均一性、借助凝胶时间的测定研究了固化剂双氰胺以及促进剂2-乙基-4-甲基咪唑对体系反应性的影响；分析讨论了含胶量对体系电性能、机械性能以及耐水性的影响，确定了合理的制作半固化片的工艺。     

国内外覆铜板文献摘录（5）

无铅化带来的变动；应用于大电流领域的高导热基板的研究；电选法回收利用废印刷线路板；废旧电脑印刷线路板金属成分溶出的试验研究；深圳市线路板蚀刻废液中铜、砷、铅、汞、镉含量调查；氢氧化铝-氮-磷环氧树脂体系的阻燃性能；纳米碳管的分散对其增强环氧树脂强度的影响；德国WEEE＆RoHS法案回顾暨荷兰废电子电机设备规范解析；含萘和脂环烃结构单元环氧树脂的固化反应及性质；不同原料合成COPNA树脂及其黏结性；环氧树脂的阻燃性研究进展；咪唑促进的含溴环氧树脂／氰酸酯体系共固化反应及其抗氧化阻燃性能研究。[编者按]     

含CF_2O桥键四氢吡喃液晶化合物的合成与性能

以对二溴苯、5-烷基-四氢吡喃-2-酮和3,4,5-三氟-2-甲基苯酚为原料,经过丁基锂反应、脱羟基、Suzuki和Williamson等共5步反应最终合成2[4′[二氟(3,4,5-三氟2-甲基苯氧基)甲基]-3′,5′-二氟-[1,1′联苯]-4-基]-5-烷基四氢吡喃类液晶化合物。反应中考察了温度、溶剂、催化剂和原料比对反应收率的影响。其中脱羟基反应滴加温度-70℃~-80℃,原料羟基化合物:三乙基硅烷:三氟化硼乙醚的摩尔比为1∶1.5∶2.5;Suzuki反应选用四(三苯基磷)钯反应收率最高;3,4,5-三氟-2-甲基苯酚的Williamson醚化最优条件为在DMSO与水的混合溶剂中醚化6h。纯化后目标产物气相色谱纯度≥99.5%,总收率约为35.6%,结构经1 HNMR及GC-MS确证。该化合物添加到液晶的基础配方中,能增加介电各向异性(Δε),降低阈值电压。     

1-丁基-3-甲基咪唑离子液体在超级电容器中的应用

两步法合成了1-丁基-3-甲基咪唑三氟乙酸盐(BMI-CF3CO2)、1-丁基-3-甲基咪唑六氟磷酸盐(BMI-PF6)及1-丁基-3-甲基咪唑四氟硼酸盐(BMI-BF4)三种离子液体,研究了这三种离子液体所制超级电容器的电化学性能。结果表明:BMI-CF3CO2在电化学稳定性及充放电效率等方面优于BMI-PF6和BMI-BF4;BMI-CF3CO2离子液体电解液电势窗口达到4.0V,所制备的超级电容器在3.6V电压下循环寿命超过1000次。     

基于液晶/聚合物光栅的可调谐双波长有机激光器

本文报道了基于液晶/聚合物光栅的可调谐双波长有机激光器的制备,并研究了激光器出射激光的电调谐以及周期调谐性能。利用激光染料4-二氰亚甲基-2-甲基-6-对-二甲基氨基苯乙烯-4H-吡喃(DCM)和有机半导体材料聚[2-甲氧基-5-(2-乙基己氧基)-1,4-苯乙炔](MEH-PPV)同时作为增益介质,液晶/聚合物光栅作为谐振腔得到可调谐双波长有机激光器,对激光器施加电压或者改变液晶/聚合物光栅的周期可调谐激光器的出射波长。双波长有机激光器从DCM和MEH-PPV中出射的激光波长分别为608.3nm和632.1nm,在外加电场的作用下,出射激光波长分别蓝移了9.6nm和1.7nm。随着光栅周期从394nm增加到406nm,出射激光波长分别红移了18.4nm和19.2nm。本工作为可调谐有机双波长激光器的研究提供了有益的指导和借鉴意义。     

国内外覆铜板文献摘录（14）

新型耐热、阻燃环氧树脂及固化剂的合成和性能研究 本文介绍了几种耐热、阻燃环氧树脂及固化剂的合成,利用各种表征手段对其固化物性能进行了研究,讨论了固化物性能同环氧树脂或固化剂结构之间的关系,并对其中部分固化体系的固化反应动力学进行了详细的研究。以1-萘酚和二环戊二烯（DCPD）为主要原料合成了一种新型含萘环和二环戊二烯环结构的环氧树脂NDEP。     

FR-4覆铜板生产技术(连载三)

(二)环氧树脂的环氧值与环氧当量环氧树脂是一种热塑性树脂,它必须加入固化剂以后才能固化成为我们需要的产品。产品的性能与环氧树脂的种类,所选固化剂的种类、固化剂的使用量及固化工艺条件密切相关。固化剂的用量通常应用当量定律,按同化剂的胺当量和环氧当量进行等当量反应,通过环氧树脂的环氧值或环氧当量,来计算配方中选用的环氧树脂的用量和固化剂的     

活性酯固化环氧基高介电常数覆铜板的研制简

当前各界对于天线设计的重点在于小型化、结构简单化及多频或宽带。高介电常数基板可以缩小微波辐射波长,达到天线小型化的目的。采用活性酯作为环氧树脂的固化剂,活性酯固化剂分子中有两个或多个具有较高活性的酯基,可以同环氧树脂进行固化反应。在同环氧树脂反应时形成不含仲醇羟基的网架,所以固化后的环氧树脂具有低的介电损耗和吸水率。采用高介电常数填料作为功能填料。研制的高介电常数覆铜板具有低的热膨胀系数、低的介电损耗和低的吸水率。     

EM环氧树脂体系中温固化反应动力学研究

介绍了一种以594为主固化制的中温固化环氧树脂体系（EM），对该体系的反应机理进行了探讨，并采用DSC分析法对体系的固化反应热动力学进行了研究，研究表明，促进剂M对594固化的环氧体系具有明显的促进作用，EM体系的热固化反应活化能为84.8KJ/mol，固化反应的反应级数为0.849。     

电子封装用环氧树脂基复合材料的优化

研究了593固化剂不同用量加入电子封装用环氧树脂E-51中的效果,以及在E-51,Al2O3复合材料中硅烷偶联剂不同用量的效果,结果显示:593固化剂与环氧树脂质量比为1:4时,复合材料的致密度高,气孔少,成型效果好;当硅烷偶联剂KH-560质量分数为8%时,复合材料的热导率达到0.75 W/(m·K).     

Moisture absorption in uncured underfill materials

This paper presents a systematic study on moisture absorption in uncured underfill based on epoxy cured with acid anhydride [methylhexahydrophthalic anhydride (MHHPA)] and epoxy cured with non-acid anhydride curing agent. The influence of absorbed moisture on curing properties, thermomechanical property, and adhesion property of underfill after curing has been investigated. For epoxy cured with non-acid anhydride, the moisture absorption is low, and the absorbed moisture has no significant effect on the properties of cured underfill materials. For epoxy cured with acid anhydride, the moisture absorption before curing can be more than 2.0%, and the absorbed moisture can affect the properties significantly. The absorbed moisture can catalyze the curing reaction between acid anhydride and epoxy. The glass transition temperature of the cured samples is reduced after the underfill absorbs the moisture before curing. The adhesion strength decreases dramatically after the underfill absorbs the moisture before curing.     

双光栅监测环氧树脂固化过程及玻璃化温度实验

为了实时监测环氧树脂的固化过程,建立了基于 光纤布拉格光栅(FBG)的固化监测系统。将裸FBG、石英毛细管封装FBG和高精度热 电阻浸入到环氧树脂及其固化剂的混合物中,一 起经历固化过 程。在升降温过程中,用热电阻监测环氧树脂内部温度变化,用波长解调仪实时测量两种FB G的波长变化。 实验结果表明,石英毛细管封装FBG监测到的温度变化趋势与热电阻监测结果相同;两种FBG 的波长差反 映了固化过程中的收缩应变,固化初期变化较大,之后逐渐减小。以玻璃态转变温度为分界 点,直接植入 环氧树脂的FBG温度灵敏度分别为石英毛细管封装FBG的5.3倍和为2.2倍。     

八维广义同步系统在伪随机数发生器中的应用

该文提出一类4维离散系统。利用系统平衡点处 Jacobi 矩阵的特征值来分析系统在平衡点处的稳定性,建立了一个判别这类系统为周期或混沌的定理。依据该定理构造了一个新的4维离散系统。该系统具有正的Lyapunov指数,数值模拟显示该系统的动力学行为具有混沌特性。结合该系统和系统广义同步定理构造了一个8维广义同步混沌系统。利用该系统构造了一个16 bit混沌伪随机数发生器 (CPRNG),其密钥空间大于21245。利用FIPS 140-2 检测/广义FIPS 140-2检测判别标准分别检测由CPRNG, Narendra RBG, RC4 PRNG和ZUC PRNG生成的1000个长度为20000 bit的密钥流的随机性。检测结果表明,分别有100%/99%, 100%/82.9%, 99.9%/ 98.8%和100%/97.9%密钥流通过FIPS 140-2检测/广义FIPS 140-2 检测标准。数值仿真显示不同密钥流之间有平均50.004%不同码。结果说明设计的伪随机数发生器有好的随机性,可以抵抗穷尽攻击。该文提出的CPRNG为密码安全的研究与发展提供了新的工具。     

Effect of spin coating on the curing rate of epoxy adhesive for the fabrication of a polymer optical waveguide

Spin coating is a simple process for rapidly depositing thin, solid polymeric films onto relatively flat substrates. Evaporation occurs during spinning of the relatively volatile species in any solution. The curing behavior of spin-coated polymeric film is influenced by the evaporation of any reactive component. An investigation was carried out on a silicon substrate to study the effects of spin coating on the curing behavior of the epoxy adhesive. The degree of curing for both spin and without spin-coated epoxy adhesive was measured by Fourier-transform infrared spectroscopy (FTIR). A slower curing reaction rate was observed for the spin-coated epoxy adhesive. The composition gradient established by solvent evaporation during spinning is responsible for the slower curing reaction rate of the spin-coated epoxy adhesive. From this study, it is proposed to use solvents that are less volatile and allow a greater part of the thinning behavior to occur without significant changes in the fluid properties during the spinning process.     

Epoxy/BaTiO/sub 3/ composite films and pastes for high dielectric constant and low-tolerance embedded capacitors fabrication in organic substrates

Epoxy/BaTiO/sub 3/ composite embedded capacitor films (ECFs) were newly designed for high dielectric constant and low-tolerance (less than /spl plusmn/5%) embedded capacitor fabrication for organic substrates. In terms of material formulation, ECFs are composed of a specially formulated epoxy resin and latent curing agent, and in terms of a coating process, a comma roll coating method is used for uniform film thickness in large area. The dielectric constant of ECF in high frequency range (0.5/spl sim/3 GHz) is measured using the cavity resonance method. In order to estimate dielectric constant, the reflection coefficient is measured with a network analyzer. The dielectric constant is calculated by observing the frequencies of the resonant cavity modes. Calculated dielectric constants in this frequency range are about 3/4 of the dielectric constants at 1 MHz. This difference is due to the decrease of the dielectric constant of the epoxy matrix. The dielectric relaxation of barium titanate (BaTiO/sub 3/: BT) powder is not observed within measured frequency. An alternative material for embedded capacitor fabrication is epoxy/BaTiO/sub 3/ composite embedded capacitor paste (ECP). It uses similar materials formulation like ECF and a screen printing method for film coating. The screen printing method has the advantage of forming a capacitor partially in the desired part. However, the screen printing makes surface irregularities during mask peel-off. Surface flatness is significantly improved by adding some additives and by applying pressure during curing. As a result, a dielectric layer with improved thickness uniformity is successfully demonstrated. Using epoxy/BaTiO/sub 3/ composite ECP, a dielectric constant of 63 and specific capacitance of 5.1 nF/cm/sup 2/ were achieved.     

Development of environmentally friendly nonanhydride no-flowunderfills

Most no-flow underfill materials are based on epoxy/anhydride chemistry. Due to the sensitizing nature, the use of anhydride is limited and there is a need for a no-flow underfill using nonanhydride curing system. This paper presents the development of novel no-flow underfill materials-based on epoxy/phenolic resin system. Epoxy and phenolic resins of different structures are evaluated in terms of their curing behavior, thermo-mechanical properties, viscosity, adhesion toward passivation, moisture absorption and the reliability in flip-chip underfill package. The influence of chemical structure and the crosslinking density of the resin on the material properties is investigated. The assembly with nonanhydride underfill shows high reliability from the thermal shock test. Solder wetting test has confirmed the sufficient fluxing capability of phenolic resins. Results show that epoxy/phenolic system has great potential for an environmentally friendly and highly reliable no-flow underfill     

Investigation on flip chip solder joint fatigue with cure-dependent underfill properties

A cure-dependent viscoelastic constitutive relation is applied to describe the curing process of epoxy underfill in flip chip on board (FCOB). The chemical shrinkage of the epoxy underfill during the curing process is applied via incremental initial strains. Thus, the stress and strain build-up, caused by the simultaneous increase in stiffness and shrinkage during the curing process, are simulated. Accelerated fatigue experiments with thermal cycles from -55/spl deg/C to 80/spl deg/C are carried out for a specially designed flip chip configuration. Based on the obtained curing induced initial stress and strain fields, thermo-mechanical predictions are presented for the test carriers. The solder bumps are modeled with temperature dependent visco-plastic properties. A combination of a Coffin-Manson based fatigue relation and a creep fatigue model is used as fatigue failure criterion. The results show that the finite element method (FEM)-based fatigue life predictions match better with the experimental results, if the curing induced initial stress state is taken into account. The effect of cure-induced hydrostatic stress is qualitatively investigated by using a modified energy partitioning damage model with a correction factor in the creep damage formulation to take into account the effect of the hydrostatic stress.     

A Novel Nanocomposite With Photo-Polymerization for Wafer Level Application

A novel nanocomposite photo-curable material which can act both as a photoresist and a stress redistribution layer applied on the wafer level was synthesized and studied. In the experiments, 20-nm silica fillers were modified by a silane coupling agent through a hydrolysis and condensation reaction and then incorporated into the epoxy matrix. A photo-sensitive initiator was added into the formulation which can release cations after ultraviolet exposure and initiate the epoxy crosslinking reaction. The photo-crosslinking reaction of the epoxy made it a negative tone photoresist. The curing reaction of the nanocomposites was monitored by a differential scanning calorimeter with the photo-calorimetric accessory. The thermal mechanical properties of photo-cured nanocomposites thin film were also measured. It was found that the moduli change of the nanocomposites as the filler loading increasing did not follow the Mori-Tanaka model, which indicated that the nanocomposite was not a simple two-phase structure as the composite with micron size filler. The addition of nano-sized silica fillers reduced the thermal expansion and improved the stiffness of the epoxy, with only a minimal effect on the optical transparency of the epoxy, which facilitated the complete photo reaction in the epoxy.