微电子封装用各向异性导电胶的研究进展

随着现代科学技术的高速发展,电子仪器正在向小型化、微型化、高集成化方向迈进。各向异性导电胶作为一种新兴的绿色环保微电子封装互连材料,广泛应用于电子产品中。介绍了各向异性导电胶的组成、分类、结构特点和导电机理,以及影响它的粘接可靠性因素,如粘接工艺参数、导电颗粒的粒径分布、各向异性导电胶的弹性模量、环境干扰等,并对国内外最新文献报道的最新研制成果进行了综述。最后,对各向异性导电胶的发展前景作了展望。     

微电子封装用导电胶的研究进展

随着现代科学技术的高速发展,电子产品向小型化、便携化和集成化方向发展。导电胶作为一种"无铅、绿色和环境友好"的新型材料取代传统的Pb/Sn材料,已成为电子工业组装材料的主流。简述了微电子封装用导电胶的组成和分类、研究进展和可靠性评估,提出了导电胶在微电子封装中的技术问题,并对其发展趋势和发展前景作了展望。     

无铅化微电子互连技术与导电胶

介绍了电子互连用导电胶(ECA)的组成和基本性能,综述了ECA在电学性能、力学性能和稳定性等方面的研究进展。随着世界范围内含铅材料的限制和禁止使用,电子制造过程中的无铅化已成为该领域的发展方向和必须面对的挑战。ECA是替代含铅钎料、实现微电子互连技术无铅化的重要发展方向。虽然目前ECA仍存在着电阻率偏高、易老化失效和电流通过能力偏低等问题,但是高性能树脂和新型导电填料的不断涌现,将为ECA性能的提高提供新的解决途径和方法。     

无铅化微电子互连技术与导电胶

介绍了电子互连用导电胶（ECA）的组成和基本性能,综述了ECA在电学性能、力学性能和稳定性等方面的研究进展。随着世界范围内含铅材料的限制和禁止使用,电子制造过程中的无铅化已成为该领域的发展方向和必须面对的挑战。ECA是替代含铅钎料、实现微电子互连技术无铅化的重要发展方向。虽然目前ECA仍存在着电阻率偏高、易老化失效和电流通过能力偏低等问题,但是高性能树脂和新型导电填料的不断涌现,将为ECA性能的提高提供新的解决途径和方法。     

提高导电胶性能的研究进展

导电胶作为一种新型的绿色微电子封装互连材料,其应用范围越来越广,并且其代替传统的Pb-Sn焊料已成为必然趋势。介绍了导电胶的研究应用现状,总结了导电胶的优点及存在的问题。综述了近几年来在提高导电胶的电导率、接触电阻稳定性以及力学性能等方面的研究进展,并展望了导电胶未来的发展方向。     

铜粉导电胶研制成功

近些年来,导电胶粘剂在微电子封装、组装行业中得到了广泛应用,目前仍以添加型导电胶占据主导地位。在各种导电胶中金粉导电胶性能最佳,但价格昂贵,应用受限;银粉导电胶效果很好,不过存在着电迁移等弊端,价也很高;铜粉导电胶的导电性能基本接近银粉导电胶,价格便宜,却因铜粉极易氧化而影响导电性能。东北大学材料与冶金学院采用硅烷偶联剂（KH-550）对铜粉进行改性处理,提高了其在导电胶中的分散性、使用过程中的抗氧化性和粘接强度。还将甲醛作为还原剂加入到树脂中,     

导电胶

导电胶代替了热焊接和高温连接操作,特别是在需要低温固化的微电子器件中——罗伯特H·威伦伯格在不能使用热焊接或高温连接的导电性连接中可以使用导电胶. 导电环氧胶可以把微电子基片粘接在一般的消费品和复杂的航空与航天用集成电路上.这些导电胶可以为钟表和计算器用发光     

固化工艺参数对导电胶的LTCC互连机械性能研究

采用导电胶的唯象模型,用COMSOL互连的有限元模型,分析了导电胶在一定的固化工艺参数(时间、压力、温度)下的剪切应力和翘曲形变,并对三个工艺参数在一定范围内,进行三因素三水平正交试验设计。研究结果表明:工艺参数组合为固化压力1 200 Pa、固化温度120℃、固化时间为10 min变形,其相应的剪切应力为2.4 412 MPa,扭曲度为2.2395E-4%,弓曲度为3.1671E-4%,为互连推荐工艺参数,该工艺参数对导电胶的固化工艺提供了参考。     

各向异性导电胶的研究与应用现状

随着微电子工业的发展,导电胶替代传统的锡铅焊料已经成为一种发展趋势,本文介绍了各向异性导电胶(ACA)的组成和分类、3种导电机理及国内外导电胶的研究现状和发展方向,特别是在各向异性导电胶填料表面功能化处理方面的研究现状和在液晶显示屏(LCD)、发光二极管(LED)组装应用上的进展。     

碳系导电胶的研究进展

介绍了导电胶的种类,重点综述了碳系导电胶[如导电炭黑导电胶、石墨导电胶、碳纳米管(CNTs)导电胶、石墨烯导电胶和碳纤维导电胶等]、复合导电胶(如Ag/CNTs导电胶、Ag/石墨烯导电胶等)的研究进展。最后对碳系导电胶的研究方向进行了展望。     

无铅电子组装材料——导电胶的研究进展

电子产品小型化、便携化、集成化的趋势和人类环保意识的增强,使传统的电子组装材料已不能满足现实的需要。导电胶作为一种无铅、绿色、环境友好的新型电子组装材料,正日益成为电子工业中组装材料的主流。该文对导电胶的组成、分类、导电机理、导电胶的导电填料、聚合物粘料、添加剂等基本组成材料和导电胶性能研究进展作了综述。引用文献43篇。     

The interrelationships between electronically conductive adhesive formulations,substrate and filler surface properties,and joint performance. Part I: the effects of adhesive thickness

Electronically conductive adhesives (ECAs) have received a great deal of attention for interconnection applications in recent years. Even though ECAs have excellent potential for being efficient and less costly alternative to solder joining in electronic components, they still possess a number of problems with respect to durability and design to meet specific needs. One of the issues that requires understanding is regarding the optimum adhesive thickness (AT) to be used. This study addresses this issue in relation to the formulations of the conductive adhesives and their interactions with adherend surfaces. For this purpose, two different adherends varying in surface characteristics were utilized along with three different conductive adhesive formulations with varying particle loadings, and shapes and sizes of conductive nickel fillers. Joints were also prepared with two different AT values, to gain insight into the influence of AT on the joint strength, deformation and joint conductivity. As the AT was increased, only a small reduction in failure load and ultimate displacement values were observed with unetched adherends. With etched adherends, however, a small increase in joint stretchability was evident with higher adhesive thickness tested at a lower crosshead speed. When the AT was increased, we also noted a corresponding increase in the initial joint resistance.     

Novel acrylic pressure-sensitive adhesive (PSA) containing silver particles

Acrylic pressure-sensitive adhesives (PSAs) are generally considered as nonelectrically conductive materials. The electrical conductivity is incorporated into acrylic polymer after blending with electrical conductive additives like silver particles. After the addition of electrically conductive silver filler, the main and typical properties of PSAs such as tack, peel adhesion, and shear strength will decline. This study is the first trial which reveals that the acrylic self-adhesive basis must be synthesized with ameliorated initial performances like high tack and excellent adhesion. Currently, the electrically conductive solvent-borne acrylic PSA containing silver fillers are not commercially available on the market. They are promising materials which can be applied for the manufacturing of diverse technical or medical high performance self-adhesive products, such as broadest line of special electrically conductive sensitive tapes.     

Conduction Efficiency and Strength of Electronically Conductive Adhesive Joints

Electronically conductive adhesives are being considered as an alternative to solder for interconnection in microelectronics. In order to gain insight regarding electrical and mechanical performance properties of this class of adhesive interconnections, overlap joints were made. Joint resistance and mechanical bond strength were measured before and after environmental stressing.     

Conduction Efficiency and Strength of Electronically Conductive Adhesive Joints

Electronically conductive adhesives are being considered as an alternative to solder for interconnection in microelectronics. In order to gain insight regarding electrical and mechanical performance properties of this class of adhesive interconnections, overlap joints were made. Joint resistance and mechanical bond strength were measured before and after environmental stressing.     

Development of Polyaniline/Epoxy Composite as a Prospective Solder Replacement Material

In this paper we present a novel application of a conducting polymer, polyaniline, as a conductive filler for the development of isotropically conductive adhesives. We have developed isotropically conductive adhesives using protonic acid-doped polyaniline as the conducting filler in an anhydride-cured epoxy system. Fundamental material characterization like DSC, TGA and SEM of the samples was conducted to study their properties. Conductivity of these materials was measured by the four probe method while impact properties were studied by lap shear and drop tests. Samples were aged at 85°C/～100% RH for more than 500 h and the effects of aging were studied. Conductivity value of 10^?3 S/cm was obtained at 25% PANI filler concentration. These results demonstrate the potential of such systems to function as isotropically conductive adhesives.     

High conductivity of isotropic conductive adhesives filled with silver nanowires

As an alternative to lead-bearing solder, isotropic conductive adhesives (ICA) have been utilized for many years in microelectronic packaging. In this study, silver nitrate (AgNO₃) as precursor, N-N-dimethylformamide (DMF) as solvent and reducing agent, preparing silver (Ag) nanowires in the nanoporous templates formed by the controlled hydrolysis and condensation of butyl titanate (Ti(OC₄H₉)₄). The Ag nanowires were characterized by X-ray diffraction and transmission electron microscopy. An isotropic conductive adhesive (ICA) has been developed by adding Ag nanowires as conductive filler. Bulk resistivity and shear strength of the ICA are measured and compared with those of conventional ICA filled with micrometer-sized Ag particles (about 1 μm) and nanometer-sized Ag particles (about 100 nm). It is found that the ICA filled with lower content of Ag nanowires exhibits lower bulk resistivity and higher shear strength than ICA filled with micrometer-sized Ag particles and nanometer-sized Ag particles. Possible conductive mechanisms of the ICA are discussed.     

Electroconductive Adhesives: Comparison of Three Different Polymer Matrices. Epoxy, Polyimide and Silicone

Electrically conductive organic adhesives are used in the microelectronics manufacturing industry for the attachment of silicon dies. These adhesives are composite materials which owe their conductivity to the incorporation of silver flakes. Several polymers have been formulated into electrically-conductive adhesives to meet different applications in the microelectronics industry; these are an epoxy resin, a polyimide and a silicone polymer. The purpose of this paper is to examine properties of these die-bonding adhesives in order to determine the advantages or disadvantages of these materials. This study offers a comparison of hardening chemistry, chemical purity, processing, electrical, thermal, and mechanical properties of three conductive adhesives based on an epoxy, a polyimide and a silicone polymer. We discuss correlation of composite properties with the structure of each matrix. The results indicate that the choice of the matrix is dictated by the application for which the electronic grade conductive adhesive is to be used and the desired properties for best reliability and performance.