Research on the inkjet printing technology of passive circuit based on nano-silver conductive ink

本文采用介观尺度的格子Boltzmann(LB)方法基于喷墨打印特征参数对多连续液滴撞击非理想壁面并融合的过程进行建模，详细研究了液滴物理特性、基材表面润湿性、液滴沉积方式等喷墨打印参数在多连续液滴融合过程中的作用，并基于理论分析结果进行多晶硅太阳能电池正面超细栅电极及导电线路的喷墨打印工艺优化研究。具体研究内容概括如下： (1) 创新性的将介观尺度的格子Boltzmann方法引入喷墨打印工艺的研究，解决了传统宏观计算流体力学方法对复杂界面融合过程难以准确捕获的难题。将基于几何描述的接触角表示方法融入伪势MRT-LB (Multiple Relaxation Time- Lattice Boltzmann)模型，实现高雷诺数、高密度比下液滴撞击非理想壁面过程的建模。对模型进行Laplace验证；接触角准确性验证；单液滴撞击非理想壁面扩展系数验证；以及双液滴在非理想壁面碰撞、融合验证，保证计算结果的准确性和可靠性。(2) 采用改进后的MRT-LB模型基于喷墨打印特征参数对多连续液滴融合成液线过程进行建模和分析。详细研究了相邻液滴间距、液滴撞击速度、前进接触角、后退接触角、液滴沉积频率等喷墨打印特征参数对多液滴融合过程的影响机理。提出获得平滑液线的最佳液滴间距公式，并首次定量研究液滴沉积频率对液线形貌的影响，提出基于液滴沉积频率的液线形貌划分方法。(3) 首次对阵列液滴在非理想壁面融合成液面过程进行建模和分析。研究了液滴间距、撞击速度、前进接触角、后退接触角等参数对液面形貌的影响机理。此外，研究了逐滴扫描沉积、逐行沉积、多级矩阵沉积、预印轮廓沉积等四种液滴沉积方法在两种纳米银墨滴喷印典型条件(0&deg;及有限后退接触角)及不同沉积频率情况下形成液面的过程，分析了各种液面形貌的形成机理。(4) 采用自主研发的高精度喷墨打印平台对无源电路喷墨打印工艺展开实验研究。提出一种交错打印方法，实现具有一定高宽比要求的多晶硅太阳能电池超细栅电极喷墨打印。</p

Numerical investigation of multi-droplets deposited lines morphology with a multiple-relaxation-time lattice Boltzmann model

The formation and morphology of multi-droplets deposited lines are investigated by employing a 3D MRT pseudopotential LB model with large density ratios and high Reynolds numbers. A geometric formulation is considered to replace the fluid-solid interaction scheme to model the contact angles hysteresis. Of particular interest in this study is to find out the optimal conditions of uniform line formation. The effects of droplet overlap ratios and advancing contact angles on the lines morphology are investigated numerically. With the droplet overlap ratio increasing, the lines morphologies including isolate, scalloped, uniform and bulging formation are quantitatively identified. An optimal droplet overlap ratio is proposed to obtain uniform morphology of lines and validated via varying Ohnesorge numbers. The effects of vertical droplet spacing on the lines morphology at the optimal droplet overlap ratio is investigated and two coalescence modes are identified. Results show that the proposed optimal overlap ratio for uniform line formation is not sufficient condition and is valid in the case of out-of-phase coalescence mode

Study of Forming Experiment of Inkjet-printed Grids for Solar Cell

采用喷墨打印技术印制太阳电池栅线具有诸多优点.在硅片上喷墨打印栅线的过程中,聚合成型的纳米银液滴之间的距离、硅片温度及栅线的重复喷印次数对栅线形貌起着决定性作用.通过改变喷印栅线控制参数的分组实验,在3D显微镜下观测栅线形貌,从而发现控制参数对栅线形貌特征的影响关系。实验结果表明,选择恰当的喷印控制参数可以制备出形貌良好的细栅线

Lattice Boltzmann study of successive droplets impingement on the non-ideal recessed microchannel for high-resolution features

Successive droplets deposited high-resolution features on the non-ideal recessed microchannel is investigated utilizing a 3D multiple-relaxation-time (MRT) pseudopotential lattice Boltzmann (LB) model with large density ratios and high Reynolds numbers. The non-ideal hydrophilic wettability is modeled by the geometric formulation within the pseudopotential LB framework. Firstly, for single droplet impingement on the square microchannel, three liquid morphologies including quatrefoil-like, quasi-square and quasi-rounded footprints are observed with varying aspect ratios of microchannel. Next, considering two successive droplets impingement on the rectangular microchannel, with the droplet spacings increasing, the liquid morphologies including bulging, uniform and dumbbell footprints are quantitatively identified. With the formation of connecting ridge, the optimal droplet spacing in in-phase collision mode is larger than that in out-of-phase mode. Besides, the deviations between simulations and theoretical values are observed which are attributed to the intensive inertial dominated flows. Finally, as extending to the multi-droplets deposited lines and films, the optimal droplet spacings are adaptive in both collision and placement modes for uniform and high-resolution features. &copy; 2017 Elsevier Lt

Laminated lithium ion battery electrode structure and ink-jet printing preparation method thereof

本发明公开了一种叠层锂离子电池电极结构及其喷墨打印制备方法，该电极结构是由若干层堆叠而成，第一种堆叠方式为：在高度方向上由电池活性材料层和导电材料层交替堆叠而成；第二种堆叠方式为：每一层由电池活性材料形成的若干圆台与导电材料形成的若干圆台在X向和Y向都呈交替排布方式，同时，在高度方向上，由电池活性材料形成的若干圆台与导电材料形成的若干圆台为交替堆叠排列方式。所述叠层锂离子电池电极结构通过喷墨打印工艺制备，通过采用多喷头的喷印工艺分别进行打印，降低了电极油墨制备过程中的复杂性，同时解决了油墨颗粒粒径偏大造成的喷头堵塞问题。</p

Lithium titanate nano printing ink for ink-jet printing, preparation method therefor and application thereof

本发明公开了一种喷墨打印用钛酸锂纳米油墨及其制备方法和应用，属于锂离子电池的电极材料技术领域。首先称取微米级钛酸锂粉末，与分散剂、粘结剂和有机溶剂混合后装入球磨容器，用氧化锆球为介质，球磨获得分散均匀的混合浆料；进一步离心获取所述喷墨打印用钛酸锂纳米油墨。所制备的纳米油墨平均粒径小于500nm，黏度10～20cps，钛酸锂浓度10～15wt.％，适用于采用喷墨打印工艺制备钛酸锂负极。由于采用低沸点溶剂，在喷印固化过程中，溶剂易于挥发，喷印的钛酸锂负极涂层活性物质含量高，涂层在粘结剂作用下与集流体形成紧密结合，大大增强了电池充放电性能。</p

Lithium titanate nano printing ink for ink-jet printing, preparation method therefor and application thereof

本发明公开了一种喷墨打印用钛酸锂纳米油墨及其制备方法和应用，属于锂离子电池的电极材料技术领域。首先称取微米级钛酸锂粉末，与分散剂、粘结剂和有机溶剂混合后装入球磨容器，用氧化锆球为介质，球磨获得分散均匀的混合浆料；进一步离心获取所述喷墨打印用钛酸锂纳米油墨。所制备的纳米油墨平均粒径小于500nm，黏度10～20cps，钛酸锂浓度10～15wt.％，适用于采用喷墨打印工艺制备钛酸锂负极。由于采用低沸点溶剂，在喷印固化过程中，溶剂易于挥发，喷印的钛酸锂负极涂层活性物质含量高，涂层在粘结剂作用下与集流体形成紧密结合，大大增强了电池充放电性能。</p