聚合物基复合封装材料导热性能的参数仿真

鉴于聚合物基复合封装材料导热性能传统研究方法的不足(效率低、预测模型不合理等),提出了一种基于VC++结合ANSYS和MATLAB联合编程的方法,对聚合物基复合材料的导热性能进行参数化有限元分析。用户只需要在由VC++开发出来的人机交互界面上输入复合材料的相关导热参数,即可由ANSYS与MATLAB相互协作完成导热模型的构建、模型导热率的数值仿真、结果输出的可视化处理等一系列工作。通过分析氮化铝填充环氧树脂复合材料的导热性能,检验了该方法的可靠性。研究结果表明,该方法不仅能够有效地预测实验结果,而且还方便易用。     

半导体封装用环氧模塑料面临绿色考验

半导体封装用环氧模塑料（EMC／Epoxy Molding Compound,通常又叫环氧塑封料）,20世纪60年代中期起源于美国（Hysol）,后发扬光大于日本,现在中国是快速崛起的世界EMC制造大国。环氧塑封料不仅可靠性高,而且生产工艺简单、适合大规模生产,同时成本较低,目前已占整个微电子封装材料97％以上市场。我国大陆EMC产能己超过7万吨,2008年将超过8万吨。随着环氧塑封行业的快速发展,对环氧塑封材料提出了更高的要求,除了提高性能、控制成本等要求外,主要集中在环境保护方面。     

“江苏省集成电路封装材料工程研究中心”在连云港华威电子集团公司破土动工

<正> “江苏省集成电路封装材料工程研究中心”经江苏省科技厅批准,近日在连云港华威电子集团有限公司破土动工。标志着我国塑封材料工业的生产、研究、开发及产业化将步入一个崭新的发展阶段。环氧模塑料是微电子工业的一种重要支撑材料。目前全世界约有90%的半导体器件采用环氧模塑料封装,塑料封装已经发展为电子工业的一个重要分支。环氧模塑料的生产也已经发展为世界工业体系中的一个新兴产业,它既属于微电子产业又属于新材料范畴。随着信息时代的到来,集成电路封装业将随着集成电路和电子技术的发展而迅速发展,由此可见,环氧模塑料的市场前景十分可观。     

IC环氧塑封料性能及其发展趋势

材料是微电子工业和技术发展的粮食，随着IC封装技术的发展，对材料特性的要求也愈来愈严格，也顺势带动封装材料发展。环氧塑封料(Epoxy Molding Compound，简称EMC)是IC后道封装三大主材料(塑封料、金丝、引线框架)之一，用环氧塑封料封装超大规模集成电路(VLSI)在国内外已成为主流，目前95％以上的微电子器件都是塑封器件。本文将简要介绍EMC配方组成、反应机理、性能之间关系及其发展趋势。     

环氧模塑料在半导体封装中的应用

环氧模塑料是一种重要的微电子封装材料,是决定最终封装性能的主要材料之一,具有低成本和高生产效率等优点,目前已经成为半导体封装不可或缺的重要材料。本文简单介绍了环氧模塑料在半导体封装中的重要作用和地位;分析了环氧模塑料性能对半导体封装的影响,并对不同半导体封装对环氧模塑料的不同要求进行了分析;最后展望半导体封装和环氧模塑料的未来发展趋势,以及汉高华威公司在新产品开发中的方向。     

环氧塑封料中填充剂的作用和发展

环氧塑封料占据整个半导体封装市场的90％左右,而填充剂含量占环氧塑封料的60％～90％,因此填充剂的性能直接影响环氧塑封料的加工性能、机械性能、导热性能和半导体器件的封装工艺性能、导热性能、可靠性能等。另外,当今社会电子技术日新月异,集成电路正向着超大规模、超高速、高密度、大功率、多功能、绿色环保化的方向发展,因此对环氧塑封料的性能要求愈来愈高,相应的填充剂性能也有了许多新的要求,并且也出现了许多新型填充剂。文中详细地介绍了环氧塑封料中填充剂的作用,各种填充剂对环氧塑封料和封装器件的性能影响以及环氧塑封料中填充剂的分类和发展。     

高频高速印制板材料导热性能的研究进展

随着电子技术的发展,对高频高速印制板导热性越来越高的要求。除了开发高成本的高导热性聚合物材料外,在聚合物中填充高导热性的无机材料也是提高高频高速印制板基材导热性能的有效方法,而且填充型复合材料可以用理论模型预测其导热系数。主要综述了填料的形貌、分布与表面改性对填充型复合材料导热系数的影响等方面的研究进展。     

塑封器件无损开封技术介绍

随着现代微电子行业的发展,对产品质量和结构安全性、使用可靠性提出了越来越高的要求。由于无损检测（NTD）技术具有不破坏试件、检测灵敏度高等优点,其应用日益广泛。塑封材料又以其低成本、生产工艺简单、适合大规模生产等特点,占据了整个微电子封装材料97％以上的市场。文章对塑封器件的开封技术及需要注意的事项进行了较详细的介绍和说明,列出了针对各种封装形式的无损开封方案,为无损开封的实际应用提供了便利。通过对塑封器件开封办法的研究,确保塑封器件的开封质量,为进一步对塑封器件进行DPA和失效分析建立了基础。     

浅议EMC在LED封装中的应用

环氧模塑料（EMC）作为一种常见的封装材料,具有可规模化生产和高可靠性等特点,被广泛应用于微电子封装领域。随着LED半导体照明技术的迅速发展,EMC作为一种新型支架塑封材料被引入到LED封装行业,成为第三代LED封装支架。与传统的PPA材料相比,EMC具有低膨胀系数、高热导率、更好的耐热性等优势。由于EMC支架是一种高度集成化的支架,具备更好的封装性能和可靠性,可进一步提升LED器件的可靠性并降低LED器件的成本。文章主要介绍EMC支架的主要特点、优势及其制作工艺,同时也总结了EMC在LED封装应用过程中还存在的一些问题。     

环氧树脂／碳纤维复合封装材料的研究

高电子及封装技术的快速发展对封装材料的性能提出了更加严格的要求，具有高导热及良好综合性能的新型封装材料的研究和开发显得更加重要。本文综述了一种新型的封装复合材料环氧树脂，碳纤维复合材料。对复合材料的热传导性能．电传导性能以及热机械性能进行了分别讨论。     

An Anisotropically High Thermal Conductive Boron Nitride/Epoxy Composite Based on Nacre‐Mimetic 3D Network

Polymer‐based thermal interface materials (TIMs) with excellent thermal conductivity and electrical resistivity are in high demand in the electronics industry. In the past decade, thermally conductive fillers, such as boron nitride nanosheets (BNNS), were usually incorporated into the polymer‐based TIMs to improve their thermal conductivity for efficient heat management. However, the thermal performance of those composites means that they are still far from practical applications, mainly because of poor control over the 3D conductive network. In the present work, a high thermally conductive BNNS/epoxy composite is fabricated by building a nacre‐mimetic 3D conductive network within an epoxy resin matrix, realized by a unique bidirectional freezing technique. The as‐prepared composite exhibits a high thermal conductivity (6.07 W m^?1 K^?1) at 15 vol% BNNS loading, outstanding electrical resistivity, and thermal stability, making it attractive to electronic packaging applications. In addition, this research provides a promising strategy to achieve high thermal conductive polymer‐based TIMs by building efficient 3D conductive networks.     

电子封装用高导热金属基复合材料的研究

高导热金属基复合材料具有优异的热物理性能,且密度较低,是非常理想的电子封装材料。但是由于其本身高的脆性和硬度,使得该材料很难通过二次机械加工成所需要的形状,严重制约了该材料的应用。本文总结了本实验室在第三代SiCp/Al电子封装材料以及第四代金刚石/Cu（或Al）电子封装材料的近净成形制备方面所取得的一些突破性成果,并就相关的关键工艺进行了讨论,论文最后对电子封装用高导热金属基复合材料未来的发展做出了展望。     

Rheology and Thermal Conductivity of Diamond Powder-Filled Liquid Epoxy Encapsulants for Electronic Packaging

The traditional silica-based epoxy system used for electronic packaging has a poor thermal conductivity of less than 1 W/mK and no longer meets the increasingly stringent thermal management requirements of many packaging applications. The current commercial availability of low-cost diamond powders with very high-thermal conductivity makes it possible to consider diamond powder-filled epoxy for high-end product packaging. This paper reports the design, rheology, and experimentally determined thermal conductivity results on the multimodal diamond powder-filled epoxy system for liquid encapsulants. Rheology studies of the monomodal diamond powder in epoxy show the necessity of the use of surfactants when the powder sizes are below 10 $mu {rm m}$. A high-thermal conductivity of 4.1 W/mK was achieved for epoxy-filled by 68% volume loading of diamond powders, which required a multimodal particle size distribution (nine sizes). Comparative measurements of electronic junction temperatures of Si diodes sealed by the diamond powder-filled epoxy and commercial silica-epoxy show a much better thermal performance of the diamond-filled epoxy, which suggests the potential application of the diamond-filled epoxy for packaging high-end electronic products.      

封装用环氧模塑料制备及其线膨胀性能研究

文章主要对集成电路封装用环氧树脂模塑料的配方进行研究,以高纯度酚醛环氧树脂为基体树脂,二甲基咪唑为催化剂,分别以结晶硅微粉、熔融硅微粉、球形硅微粉为填充料,通过改变催化剂、偶联剂、固化剂和填充料的类型或用量,并通过添加纳米二氧化硅改性剂,从而获得各配方环氧树脂模塑料扫描电子显微镜表征的微观结构、线膨胀系数等性能。进而对封装用塑料进行配方优化,获得较优配方,使环氧塑封料达到线膨胀系数小、应力低的目的,使之合乎大规模集成电路封装用模塑料的性能要求。     

电子封装用SiCp/Al复合材料的研究现状及展望

电子封装技术的快速发展对封装材料的性能提出了更为严格的要求。文章介绍了电子封装用SiCp/Al复合材料的研究现状和进展,讨论了其制备工艺和性能。文中着重介绍了空气气氛下的无压自浸渗制备方法,并进一步提出了SiCp/Al复合材料存在的主要问题以及今后的研究方向。     

航空航天用电子封装材料及其发展趋势

随着航空航天领域的迅速发展,其应用的电子器件不断微型化、高度集成化,并且可靠性要求越来越高,其电子封装材料具有更高的热导率及与芯片热膨胀系数的匹配性,还要求其电子封装材料具有更低的密度。BeO、AlN、Al/SiC与AlSi由于具有高热导率、低密度及与芯片材料良好的热膨胀匹配性,非常符合航空航天用电子封装材料的发展趋势,并已经逐步在取代常用的一些封装材料。重点介绍了四种材料的性能优势,以及它们之间的性能对比与应用前景分析。     

Estimating the Engineering Properties of Electronic Packaging Materials

Silica-filled epoxy composites represent an important class of electronic packaging materials. In this paper, a series of semi-empirical equations are proposed for estimating the density, temperature-dependant modulus, expansion coefficient and Poisson's ratio of silica-filled epoxy composites as a function of the silica content and glass transition temperature. The density and expansion coefficients are calculated using the rule of mixtures, while the composite moduli in the glassy and rubbery plateaus are derived using the Halpin-Tsai equation, the theory of rubber visco-elasticity, and elementary considerations of the polymer cross-link density. A four-parameter sigmoidal function is shown to account well for the composite stiffness in the transition region between the glassy and rubbery states, while a three-parameter single rise to maximum equation expresses the change in the composite's Poisson ratio with silica content. The models are corroborated against a large data library of actual packaging materials. Their usefulness in calculating e.g., the warpage in a plastic ball-grid array package is demonstrated in a worked example.     

电子封装用低膨胀高导热SiCp／A1复合材料研究进展

随着微电子技术及半导体技术的快速发展,高封装密度对材料提出了更高的要求。SiCP／Al复合材料具有低膨胀系数、高导热率、低密度等优异的综合性能,受到了广泛的关注。作为电子封装材料,SiCP／Al复合材料已经在航空航天、光学、仪表等现代技术领域取得了实际的应用。文章介绍了SiC颗粒增强铝基复合材料的研究现状,详细阐述并比较了几种常用的制备方法,包括粉末冶金法、喷射沉积法、搅拌铸造法、无压渗透法、压力铸造法等,进一步分析了各种方法的优缺点,并在此基础上展望了未来研究和发展的方向。     

A Roadmap Review of Thermally Conductive Polymer Composites: Critical Factors,Progress, and Prospects

Recently, the need for miniaturization and high integration have steered a strong technical wave in developing (micro-)electronic devices. However, excessive amounts of heat may be generated during operation/charging, severely affecting device performance and leading to life/property loss. Benefiting from their low density, easy processing and low manufacturing cost, thermally conductive polymer composites have become a research hotspot to mitigate the disadvantage of excessive heat, with potential applications in 5G communication, electronic packaging and energy transmission. By far, the reported thermal conductivity coefficient (λ) of thermally conductive polymer composite is far from expectation. Deeper understanding of heat transfer mechanism is desired for developing next generation thermally conductive composites. This review holistically scopes current advances in this field, while giving special attention to critical factors that affect thermal conductivity in polymer composites as well as the thermal conduction mechanisms on how to enhance the λ value. This review covers critical factors such as interfacial thermal resistance, chain structure of polymer, intrinsic λ value of different thermally conductive fillers, orientation/configuration of nanoparticles, 3D interconnected networks, processing technology, etc. The applications of thermally conductive polymer composites in electronic devices are summarized. The existing problems are also discussed, new challenges and opportunities are prospected.     

Adhesion evaluation on low-cost alternatives to thermosetting epoxy encapsulants

The thermosetting epoxy curing systems have been widely used as encapsulants in the electronic packaging industry. With the continual evolving of electronic product markets, material suppliers have been challenged to provide more options to meet the requirements of advanced, yet cost effective, packaging solutions. In this paper, two low-cost alternative materials have been investigated experimentally regarding their adhesion and reliability performance, and these have then been compared with the thermosetting epoxy systems. One of the materials is thermoplastic bisphenol A epoxy/phenoxy resin, and the other is an interpenetrating polymer network composed of an epoxy curing component and a free radical polymerizable component. Some formulations of the materials being studied could exhibit excellent adhesion, durability and application reliability. While reworkability is expected for these materials, they are promising as cost effective encapsulants for electronic packaging, and may be applied with appropriate processing techniques.