印刷参数和片基处理对银色线路质量影响的评价

Evaluation of Printing Parameters and Substrate Treatmet Over the Quality of Printed Silver Traces

印刷电子学为设计低成本的电子产品提供了一个广阔的前景。在未来几年内,采用印刷技术,在低温条件下使用纳米材料可能会带来印刷电子产业的变革。印刷电子产品可包括非常廉价的射频标签技术(RFID)、低廉的并可随意处理的显示器/电子纸、内部连接件、部分电子组件(如印刷电路板)、传感器、存储器以及耐用的用户界面。此外,印刷电路板可用喷墨印刷片基代替。直接打印的纳米粒子油墨还可用于电互连组件。在如何选择合适的材料以及如何使材料沉积和热压结更精确等方面,最大的挑战是如何确保互连部分的质量。适当的过程控制将保证印刷互连组件有适合的导电率。其中,印刷参数,如油墨温度、墨盒高度、片基温度(片基表面接受墨滴的位置是固定的)等,是印刷质量评价中应考虑的影响因素。为了使导电线路得到良好的分辨率和可重复使用的性能,这些参数非常重要。另一个关键技术是片基处理,它同样决定了线路板的质量和分辨率,由油墨与片基表面之间的化学交互作用(表面能)确定油墨附着在片基的质量。一个优化的表面可以在金属线路黏结和分辨率之间找出最佳关系。通过比较不同的表面处理方式,可以得到表面能的最佳值。常见表面处理方式有等离子处理、电晕处理和化学处理。在本研究中,对所用聚酰亚胺片表面采用电晕处理和化学溶液处理,用于评价表面能和确定最佳表面能值。

Printed electronics provide a promising potential pathway towards the design of low cost products. Manufacturing electronic devices by printing techniques using nano-size material particles at low temperatures can revolutionize the electronics industry in coming years. Products based on printable electronics might include ultra cheap radio-frequency identification（RFID） tags, inexpensive and disposable displays/electronic paper, interior connections, parts of electronic assemblies （e.g. PWB and phone chassis）, sensors, memories, and wearable user interfaces. Moreover, PWBs could be replaced by an inkjet printed substrate. Direct printing of nanoparticle inks could also be used for the electrical interconnection of components （traces）. Considering this scenario, the challenge is to provide sufficient quality of interconnecting traces considering the selection of appropriate material, more precise material deposition process and sintering. Adequate process control would lead to suitable electrical conductivity of printed interconnections. In this work the influence of the printing parameters - such as ink temperature, cartridge ink height and the plate temperature （surface over which the substrate that receives the ink is fixed） - in the print quality were evaluated. These parameters are very important in order to obtain conductive traces with good resolution and reproducibility. Another important factor is the treatment of the substrate. It also defines the quality and resolution of the traces since the chemical interaction between the ink and the surface （defined by the surface energy） determine how the ink will spread over the substrate. An optimized surface can be obtained by seeking the best relation between the metal trace adhesion and trace resolution. The surface treatment can be made in different ways aiming at an optimal value for the surface energy. Common surfaces treatments are plasma, corona treatment, and chemical treatment. In this work, polyimide substrates were submitted to surface treatment using corona and a chemical solution. The surface energy was evaluated and an optimum surface energy value was determined.