一种用于护散连接的金浆料

研制了一种用于扩散连接的金浆料。这种浆料主要由金粉和有机载体组成。浆料的烧成特性和粘度对扩散连接强度影响较大。金粉的分散性、表面形态和颗粒尺寸会影响浆料的烧成特性和粘度。载体会影响浆料的粘度。金浆料中掺入片状金颗粒能改善扩散连接强度。     

金粉形貌对金导体浆料印刷膜层性能的影响

以氯金酸为原料,研究了抗坏血酸、亚硫酸钠、草酸三种不同的还原剂对金粉形貌的影响。分别以三种金粉为导电填充料配制了适合于丝网印刷的金导体浆料,研究了金粉形貌对浆料印刷膜层性能的影响。结果表明:以明胶为分散剂、草酸为还原剂制备出的金粉所配制浆料的粘度、触变性更适合于丝网印刷工艺,其印刷膜层平整、无缺陷,烧成后膜层附着力和方阻优于抗坏血酸和亚硫酸钠作为还原剂所制备出的金粉。     

超细金粉在电子浆料中的应用

讨论了#1和#2两种超细金粉在电子浆料中的应用。#1超细金粉用于印刷型金导体浆料中,线分辨率高,性能稳定。#2超细金粉应用于焊接型金导体浆料,满足欧姆接触和附着力的要求。     

类球形金粉粒径对Au-金属化低温共烧陶瓷微观结构 及翘曲度的影响

研究和探讨了低温共烧陶瓷（LTCC）共烧过程中的收缩现象及LTCC陶瓷金属化后翘曲的主要影响因素。采用六种不同平均粒径（0.7~2.3 μm）的类球形金粉、玻璃粉及一种合适的有机载体分别制备成金导体浆料。将制备成的金导体浆料印刷在LTCC 生瓷膜上，按LTCC常规工艺叠层、共烧。分析了不同粒径金粉制备的浆料印刷在瓷片上烧结后的微观结构，测量了各瓷片的翘曲度及各浆料的方阻。实验发现采用大粒径的类球形金粉有利于减小瓷片的翘曲度，但烧结膜层致密性变差，方阻也变大。     

亚微米球形金粉的制备与应用

采用化学还原法,以草酸、亚硫酸钠和抗坏血酸(VC)等为还原剂,以PVP(聚乙烯吡咯烷酮)为分散剂还原雷酸金制备了亚微米球形金粉,利用SEM对所制金粉进行了表征。讨论了还原剂种类对金粉形貌的影响,优选出了弱还原性的VC作为制备亚微米球形金粉的还原剂。探讨了金溶液质量浓度、pH值、PVP用量对金粉粒径的影响。结果表明:当金溶液质量浓度为30 g/L,pH值为3.5,质量比ζ(PVP:Au)=0.5:1.0时,所制备的金粉具有规则的球形形貌和约0.3μm的粒径。该金粉制备的金导体浆料具有优良的导电性能。     

烧成工艺与钽钌酸铅厚膜电阻高阻特性的关系

<正> 一、前言影响厚膜电阻特性的因素是多方面的。对钽钌酸铅电阻来说,氧化钌处理温度高,阻值高、噪声大,处理温度低,阻值低,电流噪声也低。氧化钌比表面积大,阻值小;比表面积小的,阻值大。玻璃粉料的颗粒越细,阻值越高;颗粒粗,则阻值低。本文主要讨论钽钌酸铅电阻浆料同Pd-Ag导体浆料一次烧成或分次烧成与电阻特性的关系。试验发现,一次烧成的电阻与导体的端头部位有气泡产生,阻值高,噪声大。分次烧成     

电子浆料用有机载体的挥发性能

用恒温失重方法研究了70~190℃范围内,电子浆料常用松油醇乙基纤维素体系有机载体和主要溶剂的挥发特性,得到了其在一定温度下保温20min的挥发量数据和适合制作电子浆料的有机载体配方。提出了调节有机载体在不同温度下挥发量的方法,可为电子浆料烧成温度制度提供参考。在有机载体中加入超分散剂,制备绝缘介质浆料,其黏度、细度、表面张力和流变特性测试表明该有机载体配制的浆料具有假塑性流体的流变特征,印刷适性良好。     

瓷粉粒度和形貌对成瓷性能的影响

瓷粉的颗粒度分布和颗粒的形貌是瓷粉的重要特性。它们对流延的生瓷片性能、烧成后晶粒尺寸、熟瓷的致密性、熟瓷的强度、烧结温度以及烧结时x ,y,z方向的收缩率等均会产生重要的影响。本文主要介绍这些特性产生的机理和影响程度。     

金粉和玻璃粉对厚膜金导体浆料的性能影响

探讨了不同粒径的球形金粉对金导体浆料烧结膜致密性及方阻的影响，通过对比两种不同性能玻璃粉的软化点及浸润性，来讨论其质量分数的改变对金浆性能的影响。研究结果表明：选取合适粒径范围的金粉，可以提高金浆烧结膜层致密性且降低方阻；当两种玻璃的质量分数分别为w(G1)1.5%和w(G2)0.5%时，金导体浆料的方阻较小，键合拉力最大，老化拉力最好。     

MLCC钯银内电极浆料性能研究

MLCC钯银内电极浆料主要由钯银粉、有机载体和无机添加剂三部分组成.试验表明:钯银粉中钯的含量决定了浆料的烧成温度及成本价格的高低;有机载体的作用是提供浆料一定的流变性能,以满足浆料在MLCC丝网印刷时的工艺要求,有机载体触变性的大小直接影响着浆料丝印图形质量的好坏;无机添加剂的作用是抑制浆料在烧成过程中的过快收缩,选择不同的无机添加剂可以调整浆料在烧成过程中其所形成的电极层与介质层之间的烧成收缩率的匹配,避免MLCC产品由于匹配问题所引起电极开裂等质量问题.     

适合铝丝键合后热老化要求的金导体浆料

研究了一种适合铝丝键合后热老化要求的金导体浆料，性能达到使用要求。在金浆中添加了少量合金元素，并选用混合型粘结剂。对金导体铝丝焊后热老化失效机理以及添加合金元素的作用，进行了讨论     

电子浆料用超微细玻璃粉的等离子体改性

以六甲基二硅氧烷为单体,利用高频等离子体在超微细低熔磷酸盐玻璃粉体表面聚合硅氧聚合物包覆薄膜。用水和粉体压片之间的接触角变化表征了等离子体工艺参数对粉体表面能的影响。结果表明改性后粉体配制电子浆料的细度、黏度、流变特性提高显著。改性后可以改变或控制超微细粉体的表面能大小,从而可调节电子浆料的流变性和印刷适性。     

Increasing the bonding strength of chips on flex substrates using thermosonic flip-chip bonding process with nonconductive paste

Thermosonic flip-chip bonding process with a nonconductive paste (NCP) was employed to improve the processability and bonding strength of the flip-chip onto flex substrates (FCOF). A non-conductive paste was deposited on the surface of the copper electrodes over the flex substrate, and a chip with eight gold bumps bonded onto the copper electrodes by the thermosonic flip-chip bonding process.For the chips and flex substrates assembly, ultrasonic power is important in the removal of some of the non-conductive paste on the surface of copper electrodes during thermosonic bonding. Accordingly, gold stud bumps in this study were directly bonded onto copper electrodes to form successful electrical paths between chips and the flex substrate. A particular ultrasonic power resulted in some metallurgical bonding between the gold bumps and the copper electrodes, increasing the bonding strength. The ultrasonic power was not only to remove the NCP from the copper electrodes, but also formed metallurgical bonds during the thermosonic flip-chip bonding process with NCP.In this study, the parameters of the bonding of chips onto flex substrates using thermosonic flip-chip bonding process with NCP were a bonding force of 4.9 N, a curing time of 40 s, a curing temperature of 140 °C and an ultrasonic power of 14.46 W. The processability and bonding strength of flip-chips on flex substrates using thermosonic bonding process with NCP was verified in this study. This process has great potential to be applied to the packaging of consumed electronic products.     

绝缘导热浆料制备和性能

以低熔玻璃粉、金刚石粉及有机载体制备成浆料,丝网印刷在硬铝LY12基材上,烧结后制成导热绝缘层。分析了浆料中的金刚石粉含量对绝缘导热涂层导热参数和与基片附着力的影响,测试分析了浆料的流变性和触变性。结果表明,绝缘导热浆料的最佳配方为:w(有机载体)为18%;w(金刚石粉)为30%;w(低熔玻璃粉)为52%。静止时浆料中形成弱的絮凝,是剪切变稀体,有一定触变性,具有较好的丝网印刷适性。所制备绝缘涂层的热导率最高可达2.47W/(m·K)。     

Gold Stud Bumps Flip-Chip Bonded onto Copper Electrodes with Titanium and Silver Layers

The purpose of this study was to develop the thermosonic flip-chip bonding process for gold stud bumps bonded onto copper electrodes on an alumina substrate. Copper electrodes were deposited with silver as the bonding layer and with titanium as the diffusion barrier layer. Deposition of these layers on copper electrodes improves the bonding quality between the gold stud bumps and copper electrodes. With appropriate bonding parameters, 100% bondability was achieved. Bonding strength between the gold stud bumps and copper electrodes was much higher than the value converted from the standards of the Joint Electron Device Engineering Council (JEDEC). The effects of process parameters, including bonding force, ultrasonic power, and bonding time, on bonding strength were also investigated. Experimental results indicate that bonding strength increased as bonding force and ultrasonic power increased and did not deteriorate after prolonged storage at elevated temperatures. Thus, the reliability of the high-temperature storage (HTS) test for gold stud bumps flip-chip bonded onto a silver bonding layer and titanium diffusion barrier layer is not a concern. Deposition of these two layers on copper electrodes is an effective and direct method for thermosonic flip-chip bonding of gold stud bumps to a substrate, and ensures excellent bond quality. Applications such as flip-chip bonding of chips with low pin counts or light-emitting diode (LED) packaging are appropriate.     

Pb-Free Glass Paste: A Metallization-Free Die-Attachment Solution for High-Temperature Application on Ceramic Substrates

A lead-free glass frit paste as a die-attach material for high-temperature microelectronic application is proposed in this study. The glass paste containing Bi-based powder with a moderate amount of solvent was used for joining Si dice on ceramic substrates without any metallization preparation for either of the bonding surfaces. The die was bonded to a ceramic substrate at 430°C for 10 min. The study focuses on the mechanical and microstructural characterization of the joints with Si dice on two different types of ceramic substrate. Shear strength measurements were carried out at both ambient and 250°C to evaluate room- and high-temperature performance. Furthermore, the effect of aging at 300°C for 500 h on the mechanical properties is presented. The results of the mechanical and microstructural characterization demonstrate that low-temperature glass frit bonding is an effective die-attach method for harsh-environment electronic packaging.     

无铅银浆烧结工艺与导电性能研究

制备了无铅低温玻璃粉,将其与银粉和有机载体混合配制成无铅导电银浆并烧结。通过SEM和EDX观察浆料烧结银膜的形貌并进行成分分析,用四探针测试仪测量烧结银膜的电阻率,讨论了浆料成分配比、烧结时间、烧结温度等方面对银膜导电性能的影响。确定了无铅导电银浆的最佳配比为:质量分数w(银粉)72%,w(玻璃粉)3%和w(有机载体)25%,最佳烧结温度为580℃,最佳保温时间为5min。     

LTCC基板金丝热超声楔焊正交试验分析

引线键合是微组装技术中的关键工艺,广泛应用于军品和民品芯片的封装。特殊类型基板的引线键合失效问题是键合工艺研究的重要方向。低温共烧陶瓷(LTCC)电路基板在微波多芯片组件中使用广泛,相对于电镀纯金基板,该基板上金焊盘楔形键合强度对于参数设置非常敏感。文章进行了LTCC基板上金丝热超声楔焊的正交试验,在热台温度、劈刀安装长度等条件不变的情况下,分别设置第一键合点和第二键合点的超声功率、超声时间和键合力三因素水平,试验结果表明第一点超声功率和第二点超声时间对键合强度影响明显。