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71.
Thanas Budri 《Applied Surface Science》2008,254(15):4768-4773
In this paper, we summarize how the introduction of in-line TXRF monitoring provides detailed analytical information on aluminum, titanium and molybdenum contamination levels in order to improve several process steps from front-end processing, minimize product yield loss and make it possible to successfully manufacture multiple products and process geometries in the same fabrication platform. 相似文献
72.
《Microelectronics Reliability》2014,54(9-10):1977-1981
For a high robust metallization it is necessary to solve different problems related to migration mechanisms and thermo-mechanical stress in the material. Extended operating conditions and challenging assembling processes influence stress behaviour in chip corners. Typically the corner area of the chip is excluded for use. For higher stress load the forbidden area increases. But effort for demanding mission profiles of a product should not cumulative in increasing chip size. Simulation can help to a better understanding of mechanical stress in the chip corner and chip-package interaction.Corner stress relief structures lower the influence of high thermo-mechanical stress. A high functional corner stress relief structure allows a more efficient chip design. In this work of corner stress relief structure is presented and an evaluation structure is shown which allows to prove the effectiveness of the stress relief. 相似文献
73.
Four commercially available silver pastes for silicon solar cells front side metallization were examined and compared. Both rheological and printing experiments were used to correlate pastes properties and screens characteristics with printing results. Theoretical printability and spreading behavior were first characterized by means of rotational and oscillatory rheological experiments. Further on, the pastes were printed, dried, and fired in a standard solar cell process on an industrial line using a full factorial design of experiments. This methodology allows to study the effect of the paste, the screen, the aperture, and their interactions on the printing results. Especially, the finger aspect ratio, the finger cross section and its relative standard deviation, which are respectively linked to solar cell efficiency, silver consumption, and process stability, were systematically measured. This work allows finding general guidelines for process optimization. Finally, a confirmation test was carried out, leading to 19% efficiency on monocrystalline silicon solar cells in an industrial environment. 相似文献
74.
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76.
《Microelectronics Reliability》2014,54(11):2432-2439
Power MOSFET devices are extensively used in the automotive industry, but their modes of ageing are still poorly understood. Here we focus on the physical degradation mechanisms that occur in the upper Al-based metallization layer (source). This layer undergoes thermo-mechanical structural modifications due to the combination of electrical pulses and differences between the various coefficients of thermal expansion. Using electronic and ionic microscopy, we show that ageing can be divided in 2 phases where dislocation-based plasticity and then grain boundary diffusion become predominant. As a result, grain boundary grooving and surface roughening follows a partial division of the later in disconnected Al grains. Such a degradation of the metallization has been widely observed in various devices. It may lead to the observed augmentation of resistivity and also to the focusing of the various current paths, promoting hot spots and subsequent failure. 相似文献
77.
M. Hrteis J. Bartsch S. Binder A. Filipovic J. Merkel V. Radtke S. W. Glunz 《Progress in Photovoltaics: Research and Applications》2010,18(4):240-248
The properties of fine‐line printed contacts on silicon solar cells, in combination with light‐induced plating (LIP), are presented. The seed layers are printed using an aerosol system and a new metallization ink called SISC developed at Fraunhofer ISE. The influence of multiple layer printing on the contact geometry is studied as well as the influence of the contact height on the line resistivity and on the contact resistance. The dependence between contact resistance and contact height is measured using the transfer length model (TLM). Further on, it is explained by taking SEM images of the metal–semiconductor interface, that a contact height of less than 1 µm or a minimum ink amount of only 4–6 mg is sufficient to contact a large area (15·6 cm × 15·6 cm) silicon solar cell on the front side and results in a contact resistance Rc × W < 0·5 Ω cm. As the line resistivity of fine‐line printed fingers needs to be reduced by LIP, three different plating solutions are tested on solar cells. The observed differences in line resistivity between ρf = 5 × 10−8 and 2 × 10−8 Ω m are explained by taking SEM pictures of the grown LIP‐silver. Finally, the optimum LIP height for different line resistivities is calculated and experimentally confirmed by processing solar cells with an increasing amount of LIP silver. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
78.
Surface modification of polypropylene films (PP) was carried out via radiation induced graft copolymerization of 4‐vinyl pyridine (4VP) and acrylamide (AAm) to enhance the adhesion ability of the PP surface for electroless deposition of copper. Factors affecting the grafting process such as suitable solvent, comonomer composition and concentration and irradiation dose were optimized. The grafted films produced were characterized by studying their Fourier‐transform infrared (FTIR) spectra and thermal stability. The grafted films were copper‐plated by electroless deposition using Pd as the catalyst to initiate the redox reaction. The influence of catalytic activation method parameters on the plating rate were studied. Scanning electron microscopy revealed a dense and void‐free copper deposited film. The adhesion of the deposited copper film to the modified PP films was determined by measuring the tensile strength of the copper plated films. The electrical characteristics of the copper plated films in comparison with grafted films were studied. The results showed the high adhesion of the deposited copper film to the grafted PP film as well as the high electrical conductivity. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
79.
氮化铝陶瓷因其热导率高、绝缘性好以及无毒害等特点在许多领域有着广泛的应用。多层共烧氮化铝陶瓷是采用厚膜印厣j的方式将多层的电路金属化做入氮化铝基板并在特定气氛中高温烧结的一种高性能陶瓷。金属化是多层共烧氮化铝陶瓷的一个关键工艺,文章主要介绍了对金属化工艺的研究。重点研究了其中的印刷工艺、叠片层压工艺和烧结工艺。通过对印刷和烧结参数的研究,使得生产陶瓷的热导率大于170W(m·K)^-1,金属化的方阻小于18mΩ/□,金属化的抗拉力大于1.8N(1mm^2焊接面积),能满足大功率LED封装、大功率功率管封装的性能要求,已经在多种陶瓷外壳和基板中应用。 相似文献
80.
A novel electroplating indium bumping process is described,as a result of which indium bump arrays with a pitch of 100μm and a diameter of 40μm were successfully prepared.UBM(under bump metallization) for indium bumping was investigated with an XRD technique.The experimental results indicate that Ti/Pt(300(?)/200(?)) has an excellent barrier effect both at room temperature and at 200℃.The bonding reliability of the indium bumps was evaluated by a shear test.Results show that the shear strength of the ind... 相似文献