UV激光刻蚀BOPP薄膜包装特性研究

目的研究UV激光刻蚀双向拉伸聚丙烯(BOPP)薄膜后分子结构的变化,分析UV激光刻蚀对薄膜结构及透氧、透湿和力学性能等包装性能的影响,以便更好应用于食品包装领域。方法通过激光扫描显微镜分析、红外光谱分析和拉曼光谱分析,研究不同刻蚀深度薄膜表面形貌及内部分子结构变化。结果红外光谱无变化,说明无新的非极性键产生,拉曼光谱出现荧光,在1613 cm-1处的特征峰说明C=C双键出现;激光刻蚀处理可以提高薄膜透氧和透湿性能,且随刻蚀深度增加而增加,薄膜正向氧气透过性大于反向,反向水蒸气透过性大于正向;薄膜机械性能下降,刻蚀线方向与拉伸方向垂直时,其力学性能下降要大于刻蚀线方向与拉伸方向平行。结论在使用UV激光刻蚀薄膜进行包装设计时须考虑薄膜方向以及刻蚀线方向。     

KrF准分子激光直接消融深层光刻紫外光刻胶实验研究

介绍了利用激光ＬＩＧＡ工艺中的激光深层光刻技术对紫外光刻胶进行深层光刻的实验研究成果，对远紫外激光与光刻胶相互作用的机理进行了讨论，给出了ＫｒＦ准分子激光刻蚀紫外光刻胶的能量阈值以及激光能量密度与刻蚀深度的关系曲线，最后对方法的应用前景及进一步改进的设想进行了讨论。     

YBCO高温超导薄膜激光化学腐蚀进程的实验观测

提出了将激光辅助化学刻蚀技术应用于钇钡铜氧(YBCO)高温超导薄膜的刻蚀,研究了无掩膜YBCO薄膜激光化学刻蚀的表面特性及其变化规律,在激光辐照下,YBCO薄膜的液相刻蚀速率大大加快,并且在整个过程中,刻蚀速率呈现加快趋势,这一特性将有可能用于改善YBCO刻蚀中的横向钻蚀情况,并提高图形边缘的侧壁陡峭度.     

用于金属薄膜刻蚀的激光束能量分布整形研究

针对碳纤维复合材料基底上的金属薄膜图形刻蚀需求,研究了一种基于光学波前衍射变换原理的能量/激光功率密度分布整形方法,并设计制作了衍射元件。利用基模(TEM00)和非基模输出的红外激光分别进行了验证实验,用整形后的激光光束进行刻蚀,金属薄膜被完全去除,刻蚀边界锋锐整齐,基底没有可见的损伤。衍射元件对于基模模式输出激光的转换效率为71%,对非基模模式的转换效率为53%。     

激光化学刻蚀YBCO高温超导薄膜进程中电流与红外特性

利用自行研制的电流与红外实时监测系统,研究了YBCO高温超导薄膜激光辅助化学刻蚀进程中溶液腐蚀电流与红外辐射的变化规律,为YBCO激光化学刻蚀技术中激光功率选择,腐蚀液配比,温度控制以及刻蚀时间的掌握提供了重要的实验依据.主要研究结论包括:YBCO薄膜激光化学刻蚀中溶液腐蚀电流初始值较大,增长速率相对稳定,观察到"陡降峰"的出现,并与无激光辐照下的溶液腐蚀电流变化曲线进行对比,分析了可能的原因;通过对腐蚀溶液的侧面红外实时监测,观察化学热的生成及其对流情况,发现激光辐照使YBCO薄膜刻蚀速率加快,而且除激光化学作用外,腐蚀液自身温度升高也是导致刻蚀速率加快的重要因素.     

电泳法制备碳纳米管场发射阴极的研究

利用传统的电泳方法,在玻璃基片上成功地制备了场发射用碳纳米管阴极薄膜.用扫描电子显微镜和拉曼光谱观察了薄膜的形貌和结构,并测试了所制备的薄膜阴极的场发射特性.实验结果表明在玻璃的银浆导电层上沉积了一层较薄而均匀的碳纳米管膜,其场发射特性与丝网印刷工艺制备的阴极有相似甚至更佳的性能,具有更好的发射均匀性.采用电泳方法制备场发射阴极具有简单易行,成本低廉等优势,可以避免丝网印刷工艺带来的有机杂质污染和发射不均匀等问题.     

一种大面积二维石英纳米结构制备的工艺研究

介绍一种采用紫外(363.8nm)激光干涉光刻得到大面积二维纳米点阵结构的方法,该技术具有操作简单、光路搭建成本低、可以大面积加工微纳图形结构等优点;并利用等离子体刻蚀传递,获得周期为200nm的二维石英纳米点阵结构。通过光刻工艺与反应离子束刻蚀工艺的优化,得到加工二维石英点阵的最优制备工艺。利用扫描电子显微镜(SEM)与原子力显微镜(AFM)对制备二维纳米图形结构进行表征与分析,并利用紫外可见光分光光度计对制备的二维点阵结构图形进行紫外透过率测试,发现加工的二维结构在365nm处的透过率仍大于90%,符合紫外固化纳米印掩模板对紫外光高透过率的要求。     

基于增透膜的非晶硅薄膜激光低损伤晶化工艺研究

研究了一种非晶硅薄膜的激光低损伤晶化工艺方法,通过在非晶硅薄膜上淀积氮化硅薄膜方法研究激光退火改善非晶硅薄膜的质量。实验结果表明,随着激光退火频率的增加,有无增透膜样品的衍射强度均会出现先下降后上升再下降的现象。增透膜样品的最强衍射峰出现在10~15Hz激光退火后,而无增透膜样品的最强衍射峰则出现在20Hz激光退火后。SEM分析表明,应用增透膜可以降低非晶硅薄膜的激光退火脉冲频率,并减少非晶硅薄膜激光损伤,可作为一种低损伤的激光晶化工艺。     

激光刻蚀制备集成型a-Si太阳电池的一些问题

本文叙述用声光调 Q Nd:YAG 激光制造集成型 a-Si 太阳电池中的问题。在刻蚀 ITO 时,要注意掌握对应于 ITO 薄膜厚度的激光功率密度的阀值。用大于该阀值的激光功率进行刻蚀,可得到边缘平整,其中无淤积物,隔离电阻大于100kΩ 的刻槽。用 X 射线衍射和激光 Raman 谱确定了刻蚀区及其周围的晶化,二次谐波、波长为0.53μm 的激光束对 a-Si、a-SiC 的刻蚀是很有利的,因这些材料对波长0.53μm 的光的吸收系数较大,但必须提高倍频器的效率才能获得有足够功率密度的激光束。为减少集成型 a-Si 太阳电池的串联电阻,应选择适当的激光与样品的相对移动速率。对于金属背电极的选择刻蚀,为不损伤其下的 ITO 层,除控制激光功率密度外,选择短焦深的透镜并仔细调焦亦十分重要。     

低维纳米光子晶体的制备及在有机激光谐振腔的应用

采用电子束曝光技术以及反应离子刻蚀技术,提出一种简单可控、低成本制备有序排布的一维和二维光子晶体阵列的方法。通过有效的控制刻蚀工艺参数,实现对光子晶体在尺寸、周期和表面结构等进行精确控制目的。此外,以一维光子晶体为衬底,利用甩膜方法成功地制得分布反馈式高分子有机激光器。光泵结果表明,该激光染料的放大自发辐射的阈值为260kW/cm2、半波宽为0.22nm。     

Femtosecond laser induced micropatterning of graphene film

Micropatterning of CVD synthesized large area graphene film is demonstrated with femtosecond laser cutting process. Homogenous microribbon or other patterned structure can be fabricated without using any resist or other material containing the graphene surface within a very short duration. Once the suitable laser beam doses are determined, sharp edge profile and clean etching are obtained. Scanning electron microscopic study shows that the patterned microribbon is having 5 μm width and mm in length. The width of the patterned microribbon can be controlled with control of laser energy and preprogramming of laser ablation process. Raman study at the edge of the microribbon shows increase in D peak and appearance of D + G mode, signifying edge defects. The defect can be explained from the breaking of sp² carbon hybridization with oxidation due to laser etching. The Raman study shows no amorphous carbon formation with laser cutting of the graphene film. The presented process shows a simple way to make patterned microribbon on large area graphene sheet which can be extremely necessary for microelectronics fabrication.     

激光化学诱导液相腐蚀新方法

提出了一种激光诱导液相腐蚀新方法——抗蚀膜掩蔽法。抗蚀膜掩蔽法是指在激光腐蚀中,用抗蚀膜来实现对激光腐蚀区域的控制。理论分析和实验结果都表明,抗蚀膜掩蔽法可以有效地控制激光化学腐蚀的图像形状;因不需要对激光光束进行聚焦,光传播垂直于基片表面,制作出的腐蚀孔侧壁可以具有很高的垂直度;利用激光光束中心区域能量分布近似均匀的特点,使小面积腐蚀区域的腐蚀速率近似相等,腐蚀面内各点没有明显的高度差。因为以上优点,抗蚀膜掩蔽法能克服现有激光腐蚀方法的诸多弊端,简化激光腐蚀工艺,在特殊结构光电器件和光电集成中具有广泛的应用前景。     

Reducing resistance and curing temperature of silver pastes containing nanowires

Low temperature silver pastes can be widely applied on thin-film switch, flexible printing line and touch screen. In this article, we investigated printability and conductivity of silver pastes with silver wires of different diameters and content, and the conductivity of the silver pastes cured at different temperatures filled with different types silver powders and silver wires. The sheet resistance of silver pastes cured at 100 °C with Ag1 powders and Ag2 powders filled with 10 wt% silver wires of 100 nm diameters is 21.93?±?1.63 and 23.16?±?1.44 Ω/□, which is lower than the same samples cured at 135 °C without silver wire fillers. Tap density of Ag1 and Ag2 powders mixed with silver nanowires is higher than that of Ag3 powders mixed with nanowires, due to a higher filling ratio of Ag1 and Ag2 powders with silver nanowires. SEM results show silver pastes filled with Ag1 and Ag2 powders formed network when silver nanowires were added.     

Etching processes of transparent carbon nanotube thin films using laser technologies

Carbon nanotubes (CNTs) have potential as a transparent conductive material with good mechanical and electrical properties. However, carbon nanotube thin film deposition and etching processes are very difficult to pattern the electrode. In this study, transparent CNT film with a binder is coated on a PET flexible substrate. The transmittance and sheet resistance of carbon nanotube film are 84% and 1000 Ω/□, respectively. The etching process of carbon nanotube film on flexible substrates was investigated using 355 nm and 1064 nm laser sources. Experimental results show that carbon nanotube film can be ablated using laser technology. With the 355 nm UV laser, the minimum etched line width was 20 μm with a low amount of recast material of the ablated sections. The optimal conditions of laser ablation were determined for carbon nanotube film.     

Preparation of silver nanoparticles dispersed in polyacrylonitrile nanofiber film spun by electrospinning

Ag nanoparticles dispersed in polyacrylonitrile (PAN) nanofiber film spun by electrospinning were in situ prepared by reduction of silver ions in N₂H₅OH aqueous solution. The Ag/PAN nanocomposite film was characterized by UV absorption spectroscopy, transmission electron microscopy (TEM) and surface-enhanced Raman scattering (SERS) spectroscopy. UV spectrum and TEM image show that silver nanoparticles with average diameter of 10 nm were obtained and dispersed homogeneously in PAN nanofibers. SERS spectrum indicates that the structure of PAN has been changed after Ag nanoparticles are dispersed in PAN.     

Controllable assembly of silver nanoparticles induced by femtosecond laser direct writing

We report controllable assembly of silver nanoparticles (Ag NPs) for patterning of silver microstructures. The assembly is induced by femtosecond laser direct writing (FsLDW). A tightly focused femtosecond laser beam is capable of trapping and driving Ag NPs to form desired micropatterns with a high resolution of ∼190 nm. Taking advantage of the ‘direct writing’ feature, three microelectrodes have been integrated with a microfluidic chip; two silver-based microdevices including a microheater and a catalytic reactor have been fabricated inside a microfluidic channel for chip functionalization. The FsLDW-induced programmable assembly of Ag NPs may open up a new way to the designable patterning of silver microstructures toward flexible fabrication and integration of functional devices.     

Controllable assembly of silver nanoparticles induced by femtosecond laser direct writing

Abstract

We report controllable assembly of silver nanoparticles (Ag NPs) for patterning of silver microstructures. The assembly is induced by femtosecond laser direct writing (FsLDW). A tightly focused femtosecond laser beam is capable of trapping and driving Ag NPs to form desired micropatterns with a high resolution of ～190 nm. Taking advantage of the ‘direct writing’ feature, three microelectrodes have been integrated with a microfluidic chip; two silver-based microdevices including a microheater and a catalytic reactor have been fabricated inside a microfluidic channel for chip functionalization. The FsLDW-induced programmable assembly of Ag NPs may open up a new way to the designable patterning of silver microstructures toward flexible fabrication and integration of functional devices.     

Oxygen plasma etching of silver-incorporated diamond-like carbon films

Diamond-like carbon (DLC) film as a solid lubricant coating represents an important area of investigation related to space devices. The environment for such devices involves high vacuum and high concentration of atomic oxygen. The purpose of this paper is to study the behavior of silver-incorporated DLC thin films against oxygen plasma etching. Silver nanoparticles were produced through an electrochemical process and incorporated into DLC bulk during the deposition process using plasma enhanced chemical vapor deposition technique. The presence of silver does not affect significantly DLC quality and reduces by more than 50% the oxygen plasma etching. Our results demonstrated that silver nanoparticles protect DLC films against etching process, which may increase their lifetime in low earth orbit environment.     

Laser direct write patterning technique of indium tin oxide film

The circuit patterns of transparent conductive oxide films (TCO films) have widely formed using the traditional photolithography method. The indium tin oxide (ITO) films of flat panel displays are one of the TCO films and usually ablated using the wet etching, which is widely adopted in the semiconductor processing. However, the chemical wet etching techniques usually appear with more disadvantages in the procedure, including the chemical pollution, the under-cut effect, the swelling and the costly. Therefore, the dry etching would be replaced the photolithography procedures. The laser directing method is one of the dry etching techniques and could form the circuit pattern on the ITO glasses. Moreover, the laser directing techniques could flexibility make the circuit pattern in the TCO film and the substrate would be not eroded by the laser ablation. The investigation is interested in circuit patterning of glass substrate using the laser direct writing techniques to ablate the ITO films by a UV laser materials processing system. The UV laser is a third-harmonic Nd: YAG laser with a 355 nm of wavelength and the power is 1.0 W. In this paper, the ITO films are ablated by the UV laser materials processing system which used the different repetition rate and the feeding speeds of tables. The results of laser pattering of ITO films are measured using the optical microscope (OM) and the scanning electron microscope (SEM), and it indicates the repetition rate of laser would affect the width of line.     

Reactive ion etching of thin chromium films using a two-layer resist system of polyimide and evaporated silver halide

The process of r.f. reactive ion etching (RIE) of chromium photomasks with the use of a two-layer resist system consisting of a submicron thick silver halide film evaporated onto a polyimide sublayer was investigated. The two-layer resist system proposed here combines the high resolution and sensitivity to light and electron irradiation of the silver halide film with the great masking ability of the polyimide layer during RIE. The temperature stability of the polyimide layer was investigated and compared with that of the conventional photoresist (Shipley AZ1350J).The dependence of the etching rate of these materials in both oxygen and Freon-12 (CF₂Cl₂) gases on the r.f. power was determined. It was found that the thermal stability and masking ability against the intensive RIE processes of the two-layer system developed are up to three times greater than those of the conventional photoresists. The microstructure in the chromium photomasks with the minimum line size of 0.75 μm obtained by UV contact printing and RIE is presented in scanning electron micrographs. It is shown that the two-layer resist system comprising an evaporated silver halide film and a masking polyimide sublayer represents a new alternative in RIE of microstructures with micron and submicron dimensions.