引线键合中第一点勾线力的影响因素

勾线拉力测试是评估引线键合质量的一种主要方法,同时影响测试结果的因素有很多.文章通过理论分析和实际测量,发现封装结构、线弧高度和勾线位置对第一焊点的勾线力有显著影响.Non-EP结构中线弧的第一点勾线力比EP结构中的大;随着线弧高度的增加,线孤的第一点勾线力将逐渐变大;在勾线位置由第一焊点逐渐移至线弧中间位置时,一般高...     

国际金融危机下封装测试行业面临的挑战

受国际金融危机影响,2008年国内集成电路产业增长率大幅度滑坡,封装测试行业也同样面临巨大挑战。文章分析了2008年国内集成电路产业尤其是江苏省集成电路产业的发展现状,封测业仍保持增长,但也出现明显下滑。原因不仅有国际环境的影响,还与国内集成电路产业特点有关。文章进一步探讨了金融危机的特点和对国内半导体行业的影响,以及国家目前为应对危机出台的各项政策。在此基础上,文章预测2009年半导体业将继续下降,但中国的半导体产业会先于全球半导体产业恢复,并高于全球半导体产业的增长幅度。最后,文章从技术、人才和资金三方面提出了封装测试业应对危机的措施,强调走出这次产业低谷的关键还是要依靠政府的强有力政策措施,即快速拉动国内需求。     

Testing of polybutylene succinate based films for poultry meat packaging

Overall evaluation of the newly developed materials based on polybutylene succinate (PBS) and polybutylene succinate-co-adipate (PBSA) derived from renewable resources was carried out. This study was focused on the practical examination of two selected double layer materials - i) PBSA/(90% PBS + 10% PBSA) and ii) PBSA/(80% PBS + 10% PBSA + 10% talc), which were applied for vacuum packaging of raw chicken and turkey meat and smoked turkey meat. Physical, chemical and mechanical properties of these materials were compared with commonly used packaging material based on polyamide/polyethylene (PA/PE). Functional parameters of packaging materials such as the film thickness, water vapour transmission rate, oxygen permeability, tensile strength, transmittance and overall migration were tested. Various values of water vapour transmission rate for PA/PE, i) PBSA and ii) PBSA 2.1, 20.9 and 21.0 g·m^−2·d⁻¹; oxygen permeability 74.7, 115.4 and 85.1 ml (STP)·m⁻²·d⁻¹·0.1 MPa⁻¹ (all at 23 °C, 75% relative humidity) and transmittance 82.6, 15.7 and 6.9% were found, respectively. For the packaged meats only minor changes of pH, water activity, microbiological quality, colour and profiles of volatile compounds during the storage throughout their shelf life were found. Results of all experiments confirm that even if the physical, chemical and mechanical properties of commonly used PA/PE and new PBS packaging materials are not the same, there is no significant limitation in the practical application of PBS based films for raw and smoked poultry meats.     

Photografting Coating: An Innovative Approach to “Non-Migratory” Active Packaging

The increasing trend of sustainability (single-use packaging), safety (fresh consumption), and convenience (processing and application) in packaging science has created a high demand for packaging materials with advanced functions. Thus, the challenges involved with conventional active packaging, for example, migration, low efficiency, upscaling difficulty, safety, and regulations should be addressed through an industrial scalable method, such as photografting coating. Photografting coating, which involves a strong surface covalent linkage, can be employed for preparing novel “non-migratory” active packaging systems with strong antimicrobial and self-cleaning, antifouling and self-defensive, metal chelating as antioxidant, free-radical scavenging as antioxidant, biocatalytic, and easy printing properties. Herein, profound insights into the technique of photografting coating are provided, with a focus on its application potential in non-migratory active packaging. The scientific explanation for the photografting coating technique and its application feasibility are illustrated to introduce its potential to confer new functions onto packaging materials. Furthermore, the recent progress, application functions, process, and safety challenges, as well as future directions of photografting coating in the preparation of non-migratory active packaging systems are explored in detail.     

Formation of Polyvinyl Alcohol film with graphene nanoplatelets and carbon black for electrostatic discharge protective packaging

This research investigated the synergic effect of graphene nanoplatelets (GNPs) and carbon black (CB) as a blended conductive filler for polymer film used as electrostatic discharge (ESD) packaging materials. Various weight ratios of GNPs/CB and combined filler concentrations were mixed and processed into Polyvinyl Alcohol (PVOH) based film. The surface resistivity and volume resistivity of the resulting film was measured under three different humidity environments. The study found that the composite with GNPs/CB ratios of 10:90 and 30:70 resulted in a sharp drop in surface resistivity by 5–8 orders of magnitude at the filler loading 8-10 wt%. The volume resistivity of the resulting film exhibited steady and consistent ranges within 10⁸–10¹² Ω cm across all loadings. The difference in conductivity between surface and volume made the film possible to be used in protecting equipment against electrostatic discharges inside of a package. The high loading of GNPs in hybrid GNPs/CB had no effect on enhancing both surface and volume conductivity of the composite film.     

食品包装材料与容器涂料中甲醛的示波极谱测定方法的研究

在ｐＨ５．０的０．０２ｍｏｌ／Ｌ乙酸－乙酸钠介质中,甲醛与硫酸肼的反应产物在－１．０４Ｖ处产生一个灵敏的吸附还原波,其峰高（ｉｐ）与甲醛浓度在０．０１～１．０ｍｇ／Ｌ范围内呈良好的线性关系。方法操作简便、快速、灵敏、选择性好。用于食品包装材料、容器内壁涂料中游离甲醛的测定,均获得与国标法一致的效果。     

Antimicrobial ZnO Nanoparticle–Doped Polyvinyl Alcohol/Pluronic Blends as Active Food Packaging Films

Today, plastic waste has been highlighted as one of the greatest threats to the environment. These environmental concerns and the increased necessity for safe food packaging have inspired scientists to focus on the development of active biodegradable materials. Herein, a novel poly(vinyl alcohol)/pluronic/ZnO nanocomposite film (PVA/PLUR/ZnO) is introduced as an active packaging material with enhanced antimicrobial activity. Gamma irradiation is used as a “green” route to prepare ZnO nanoparticles via a polymer pyrolysis method. The as-prepared ecofriendly ZnO nanoparticles are characterized and incorporated into the PVA/PLUR matrix in different concentrations. Transmission electron microscopy and dynamic light scattering measurements prove that ZnO nanoparticles have a mean particle size of 30 nm with a spherical-like morphology. Morphological and structural characterization confirm the successful incorporation of ZnO into the PVA/PLUR matrix, which in turn enhances the thermal and barrier properties of PVA/PLUR/ZnO nanocomposite films. On the other hand, the opacity of blends is increased. The PVA/PLUR/ZnO composites exhibit broad-spectrum antimicrobial activity against Gram-positive, Gram-negative bacterial pathogens, and fungi, and the activity increases with increasing concentrations of ZnO nanoparticles. These results introduce PVA/PLUR/ZnO films as effective antimicrobial materials for active food-packaging applications.     

光学方法在微电子封装中的应用

热应力分析在微电子封装的设计和制造中是非常重要的一环。影响微电子封装可靠性的因素包括封装结构中的温度分布、热致变形和关键界面上的层间粘结强度。在微电子封装热应力分析和可靠性评估中，实验力学起着重要的作用。凭借其内在的并行处理能力，实验力学中的光学方法可以提供现场的、具有各种敏感度和解析度的全场位移测量，因而它也被广泛地用于微电子封装领域。本文讨论了光学方法在微电子封装热应力分析中的应用，并举实例来说明光学方法是如何地被用于微电子封装技术的研发以及考核验收。     

Coupling Fibers to Planar Waveguides Using a High-Temperature Epoxy

Computer simulation was used to understand the adhesive-based coupling of optical fibers to planar waveguides with a view to adhesive development. Satisfactory coupling performance could be achieved with facet-angled fibers and waveguides, regardless of the adhesive’s index and optical loss. A high-temperature epoxy adhesive was developed for coupling applications based on the simulation. The adhesive is able to achieve a material-related loss of ?0.05 dB and a back-reflection loss of less than ?50 dB in the coupling. In addition, the adhesive has excellent mechanical and thermal properties and can easily meet the Telcordia standard GR1221 while withstanding high temperatures and high optical power.     

A simple method to unwrap the geometrically discontinuous phase map and its application in the measurement of IC package

Research on the techniques to unwrap the geometrically discontinuous phase map is an active area during the past decade, various algorithm are developed. Basically, these algorithms need a prior knowledge about the spatial extension of the discontinuity area in the sample for correct phase unwrapping, manual mask is often involved and negate the sense of automatic processing to fringe patterns. More ever, current phase unwrapping algorithms are either computationally complex or highly time consuming. In this paper, a refined method is proposed to deal with the geometrical discontinuity problem in an improved automation sense: suppression of background noise and recognition of discontinuity area in the phase map can be finished in the same time, and discontinuous phase map can be unwrapped in a simple way to avoid the effect of discontinuity area. An example of electronic package with complex shape and structure is used to verify the efficiency of this method.