基于退化数据的厚膜电阻可靠性评估

设计了厚膜电阻的高温贮存试验,以评估厚膜电阻的可靠性。基于阻值的退化数据,采用线性退化模型描述厚膜电阻的退化过程,结果表明,厚膜电阻伪寿命分布满足对数正态分布规律。结合Arrhenius模型推算得出,厚膜电阻在室温下的寿命约为17.8年。分析了厚膜电阻的失效机理,完成了厚膜电阻在温度应力下的可靠性评估。     

厚膜电阻例行可靠性实验噪声特性研究

厚膜电阻器是混合集成电路中最重要的元件之一。厚膜电阻器以其价格低廉、性能稳定和可靠性高而备受电路设计者的青睐。但是，厚膜电阻器的噪声大是不争的事实。为了能够在精密电路中应用，必须测量和控制电阻器的噪声。近年来，国内外学者发现厚膜电阻器的噪声与厚膜材料结构和质量有密切关系。本文通过厚膜电阻器例行可靠性实验中噪声测量和分析，与常规测量参数对比，探索噪声用于厚膜电阻器例行可靠性实验表征的可行性。     

厚膜金导体的可靠性试验

介绍了厚膜金导体可靠性试验方面的一些研究结果。对金的电化学迁移以及厚膜金导体的热试验进行了分析 ,并讨论了在工艺过程中应注意的一些问题。     

厚、薄膜电阻激光快速微调技术

详细介绍了激光微调厚薄膜电阻的基理、激光调阻系统的构成、激光器选择、光束定位扫描系统及实时检测原理,并给出了调阻过程中各种相关参数。     

薄膜电阻网络稳定性和可靠性研究

本文通过对薄膜电阻网络稳定性和可靠性的研究，分析了影响薄膜电阻网络稳定性和可靠性的因素。通过在蒸发过程中合理地控制几个关键工艺参数、选择合适的热处理条件等方法，能够实现电阻网络长期稳定性和可靠性的提高。     

厚膜功率电阻的制作工艺及控制方法

本文从分析电阻浆料的性能及常用电阻图形的设计入手,对厚膜功率电阻的制作工艺进行了研究,提出了其工艺控制方法,并在实际工程中得到应用,得到了满意的效果。     

Preliminary assessment of the stability of thin- and polymer thick-film resistors embedded into printed wiring boards

Embedding passive components into multilayer printed wiring boards (PWBs) meet electronic device requirements concerning the necessity of saving the surface board area for active elements, reducing board’s size, improving device functionality and safety as well as overall product cost reduction. Since embedded components cannot be replaced after the board is completed, a long term stability and reliability are the important concerns for manufactures.This paper presents the results of examinations of embedded thin-film NiP resistors and polymer thick-film resistors during their continuous operation and the influence of temperature on the resistance values after the simulation of a lead-free soldering process and after the temperature cycling test (?40 ?C/+85 ?C).     

Enhanced efficiency and stability of polymer solar cells with TiO2 nanoparticles buffer layer

TiO₂ sols synthesized with a facile solution-based method were used as a buffer layer between the active layer and the cathode Al in conventional structure polymer solar cells (PSCs). Using transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) and atomic force microscopy (AFM), the morphological and crystallographic properties of synthesized TiO₂ nanoparticles (TiO₂ NPs) as well as the buffer layer were studied in detail. It was observed that by increasing H₂O in the process of peptization both the crystallinity and particle size of TiO₂ NPs were enhanced, while the particles in sol showed a narrower size distribution conformed by dynamic light scattering. Inserting TiO₂ NPs as a buffer layer in conventional structure PSCs, both the power conversion efficiency (PCE) and stability were improved dramatically. PSCs based on the structure of ITO/PEDOT:PSS/P3HT:PCBM/TiO₂ NPs/Al showed the short-circuit current (J_sc) of 12.83 mA/cm² and the PCE of 4.24%, which were improved by 31% and 37%, respectively comparing with the reference devices without a TiO₂ buffer layer. The stability measurement showed that PSC devices with a TiO₂ NPs buffer layer could retain 80% of the original PCEs after exposed in air for 200 h, much better than the devices without such a buffer layer. The effect can be attributed to the protection by the buffer layer against oxygen and H₂O diffusion into the active layers. The observations indicate that TiO₂ NPs synthesized by facile solution-based method have great potential applications in PSCs, especially for large-area printed PSCs.     

Insights into the influence of fluorination positions on polymer donor materials on photovoltaic performance

To explore the influence of fluoro substitution position and number on optical, electrochemical and photovoltaic properties, three novel donor-acceptor (D-A) alternative copolymers (PHF, PFH and PFF) were synthesized by Stille polycondensation of 2,3-diphenyl-5,8-di(thiophen-2-yl)quinoxaline (DTQx) acceptor unit and indacenodithiophene (IDT) donor unit. As films, PHF and PFF comprising two fluoro substituents on the lateral phenyl groups displayed a broad absorption ranging from 350 to 700 nm; whereas PFH containing two fluorine atoms on the polymer main chain exhibited a slightly narrower absorption ranging from 350 to 650 nm. In addition, fluoro substitution on the polymer main chain can lower the HOMO level of the resulted polymers. As expected, PFH and PFF possess deeper HOMO energy level than PHF. Polymer solar cells (PSCs) were fabricated with these three polymers as donor materials and PC₇₁BM as acceptor material. PHF based PSCs gave a power conversion efficiency (PCE) of 7.2% with a V_oc of 0.84 V, a J_sc of 12.46 mA/cm² and an FF of 0.69. And PFH based PSCs showed a PCE of 6.19% with a V_oc of 0.93 V, a J_sc of 9.57 mA/cm² and an FF 0.70. However, a PCE of only 2.9% with a V_oc of 0.92 V, a J_sc of 4.61 mA/cm² and an FF of 0.68 was obtained for PFF based PSCs. Transmission electron microscopy (TEM) and resonant soft X-ray scattering (R-SoXS) studies indicated that the introduction of four fluorine atoms at each repeating unit can spoil the morphology of active layer. These results highlight the importance of fluorination position and number to the performance of PSCs.     

Using d-limonene as the non-aromatic and non-chlorinated solvent for the fabrications of high performance polymer light-emitting diodes and field-effect transistors

Aiming to environment protection, green solvents are crucial for commercialization of solution-processed optoelectronic devices. In this work, d-limonene, a natural product, was introduced as the non-aromatic and non-chlorinated solvent for processing of polymer light-emitting diodes (PLEDs) and organic field effect transistors (OFETs). It was found that d-limonene could be a good solvent for a blue-emitting polyfluorene-based random copolymer for PLEDs and an alternating copolymer FBT-Th₄(1,4) with high hole mobility (μ_h) for OFETs. In comparisons to routine solvent-casted films of the two conjugated polymers, the resulting d-limonene-deposited films could show comparable film qualities, based on UV–vis absorption spectra and observations by atomic force microscopy (AFM). With d-limonene as the processing solvent, efficient blue PLEDs with CIE coordinates of (0.16, 0.16), maximum external quantum efficiency of 3.57%, and luminous efficiency of 3.66 cd/A, and OFETs with outstanding μ_h of 1.06 cm² (V s)⁻¹ were demonstrated. Our results suggest that d-limonene would be a promising non-aromatic and non-chlorinated solvent for solution processing of conjugated polymers and molecules for optoelectronic device applications.