共查询到17条相似文献,搜索用时 312 毫秒
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随着微电子封装技术的发展,各向异性导电胶作为一种绿色的连接材料,广泛应用于电子产品中。文中主要介绍各向异性导电胶互连器件的粘接原理和影响其可靠性的各种因素,如粘接工艺参数、外界环境的干扰、各向异性导电胶的物理特性等。 相似文献
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本文讲述了微组装中粘接技术需采用性能良好的导电胶,从粘接理论入手,结合实施结果和实践经验,详细论述了如何选择适当的导电胶,并具体分析了粘接工艺中胶层厚度,固化温度、时间、压力及粘接表面对粘接强度,导电性、导热性和可靠性等的影响。 相似文献
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微波芯片元件的导电胶粘接工艺与应用 总被引:1,自引:0,他引:1
导电胶常用于微波组件的组装过程,其粘接强度、导电、导热和韧性等性能指标严重影响其应用范围.分析了导电胶的国内外情况和主要性能参数,总结了混合微电路对导电胶应用的指标要求.通过微波芯片元件粘接工艺过程,分析了导电胶的固化工艺与粘接强度和玻璃化转变温度的关系、胶层厚度与热阻的关系、胶点位置和大小与粘片位置控制等方面的影响关系.测试结果显示,经导电胶粘接的芯片元件的电性能和粘接强度等指标均满足设计和使用要求,产品具有较好的可靠性和一致性. 相似文献
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Bin Xie Shi X.Q. Han Ding 《Components and Packaging Technologies, IEEE Transactions on》2008,31(2):361-369
In an anisotropic conductive adhesive (ACA) assembly, the electrical conduction is usually achieved with the conductive particles between the bumps of integrated circuit (IC) and corresponding conductive tracks on the glass substrate. Fully understanding of the mechanical and electrical characteristics of ACA particles can help to optimize the assembly process and improve the reliability of ACA interconnection. Most conductive particles used in the ACA assembly are with cracks in the metal coating of the particles after the ACA bonding. This paper introduced the fracture analysis by applying the cohesive elements in the numerical model of the nickel-coated polymer particle and further simulating the cracks initiation and propagation in the nickel coating during the ACA bonding. The simulation results showed that the stress distribution on the nickel-coated particle with cracks was significantly different from that on the nickel-coated particle without crack, indicating that the stress analysis by taking the crack into consideration is very important for the reliability assessment of the ACA interconnection. The stress analysis of cohesive elements indicated that the cracks initiated at the central area of the nickel coating and propagated to the polar area. Furthermore, by the introduction of a new parameter of the virtual resistance, a mathematical model was established to describe the electrical characteristics of the nickel-coated particle with cracks. The particle resistance of the nickel-coated particle with cracks was found to be much higher than that of the particle without crack in the optimized bonding pressure range, indicating that it is necessary to take the crack into consideration for the particle conduction analysis as well. Therefore, the fracture analysis on the conductive particle by taking the crack into consideration could accurately evaluate the reliability of ACA interconnection and avoid serious reliability issues. 相似文献
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The flip chip bonding process using anisotropic conductive adhesives (ACA) and the consequent joint reliability were studied. The substrates used were rigid FR-4 boards, which are interesting due to their low cost and wide range of applications. The problems associated with the technique are discussed in this paper from the reliability point of view. Also, some aspects concerning production are introduced.The reliability of the joints was studied by accelerated environmental tests. A temperature cycling test was performed between temperatures −40 and +125 °C. Constant humidity testing was conducted at 85 °C and RH85%. In addition, reflow aging tests were performed using a conventional Sn/Pb reflow profile. For reducing the bonding cycle time, a two-stage curing process was used, which also utilizes the reflow process.The results show that the three bonding parameters, temperature, time, and pressure, all affect joint reliability. Most detrimental, however, seems to be reflow treatment performed after bonding. Most failures occurred only very briefly during the temperature cycling at the moment the temperature changed, while the joints were still conducting at both temperature extremes. However, a different failure mechanism caused a different kind of behavior during temperature cycling. The relationship between the failure modes and the failure mechanisms was studied using a scanning electron microscopy. 相似文献
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A reliable copper wafer bonding process condition, which provides strong bonding at low bonding temperature with a short bonding
duration and does not affect the device structure, is desirable for future three-dimensional (3-D) integration applications.
In this review paper, the effects of different process parameters on the quality of blanket copper wafer bonding are reviewed
and summarized. An overall view of copper wafer bonding for different bonding parameters, including pressure, temperature,
duration, clean techniques, and anneal option, can be established. To achieve excellent copper wafer bonding results, 400°C
bonding for 30 min. followed by 30 min. nitrogen anneal or 350°C bonding for 30 min. followed by 60 min. anneal bonding is
necessary. In addition, by meeting the process requirements of future integrated circuit (IC) processes, the best bonding
condition for 3-D integration can be determined. 相似文献
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《Microelectronics Reliability》2014,54(9-10):2058-2063
Thin chips are an interesting option for reducing the thickness of an electronics package. In addition to the reduced size, thinned chips are flexible and can dissipate more heat than thicker ones. Joining of the thin chips can be done using several different techniques. Of these, anisotropic conductive adhesives (ACA) are an interesting option as they have several advantages, such as low bonding temperature and capability for high density interconnections. The reliability of ACA flip chip joints under thermal cycling conditions has been found to increase when thinned chips are used. However, the effect of humidity has not been fully explored. In this study the reliability of thinned chips (50 μm) under humid conditions was investigated using thin flexible substrates. Seven test lots were assembled with thinned chips using two different ACA films and liquid crystal polymer (LCP), polyimide (PI) and thin FR-4 substrates. A high humidity and high temperature test was used to study the reliability of the interconnections. A finite element model (FEM) was used to analyse the stresses in the test samples during testing. Several failures occurred during the test and significant differences between the substrates were seen. Additionally, bonding pressure was found to be a critical factor for the reliability under the humid conditions. 相似文献
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For the highly reliable interconnection in a micro-packaging technology requiring an excellent electrical and mechanical performance, the new anisotropic conductive adhesive (ACA) system with a low melting point solder was designed and characterized. An optimum flip-chip bonding cycle considering the chemo-rheological properties of a polymer matrix and solder was proposed. The bonding mechanism of the new ACA system was experimentally observed by the optical microscope. The electrical properties such as electrical resistance of about 5.6 mΩ and current density of 10,000 A/cm2 were measured by the 4-point probe test. The measured shear strength was 304 MPa after bonding process.Electrical and mechanical performances were measured and compared before and after a pressure cooker test (PCT). In order to get a more stable ACA system during processing, the polymer matrix mixed with a reductant and a low melting point solder powder will be continuously developed in the near future. 相似文献
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《Components and Packaging Technologies, IEEE Transactions on》2006,29(3):528-534
An accurate characterization for the deformation behavior of conductive particles is important: 1) to understand the anisotropic conductive adhesive (ACA) interconnection and 2) to optimize the ACA bonding parameter. This paper introduces an experimental technique, which has been developed to allow continuous monitoring of deformation characteristics of a single conductive particle. The load-deformation curve of a single conductive particle is measured, which provides the quantitative estimation of the mechanical and electrical characteristics of metal-coated polymer spheres used in ACAs. Based on the load-deformation result of a single conductive particle and the number of trapped particles on a bump, equivalent spring models are used to predict the deformation degree of conductive particles after flip chip assembly. For two kinds of conductive particles with different polymer cores, the mechanical and electrical characteristics of ACA interconnection were studied. Such results are used to further achieve a more sophisticated approach of the ACA bonding process and contact reliability. 相似文献
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Some of the current assembly issues of fine-pitch chip-on-flex (COF) packages for LCD applications are reviewed. Traditional underfill material, anisotropic conductive adhesive (ACA), and nonconductive adhesive (NCA) are considered in conjunction with two applicable bonding methods including thermal and laser bonding. Advantages and disadvantages of each material/process combination are identified. Their applicability is further investigated to identify a process most suitable to the next-generation fine-pitch packages (less than 35 mum). Numerical results and subsequent testing results indicate that the NCA/laser bonding process is advantageous for preventing both lead crack and excessive misalignment compared to the conventional bonding process 相似文献