Abstract: With the progress of society and the development of science and technology, people’s demands for health, quality of life, and safety are steadily increasing. Smart clothing, a novel product integrating technology and fashion, has gradually entered people’s lives. It seamlessly combines technology and fashion. By embedding sensors, circuits, microprocessors, and other components, it fulfills functions such as interacting with the wearer, monitoring health status, and enhancing athletic performance. Smart clothing has emerged as a significant trend in the future development of the clothing industry. The design of smart clothing must balance human comfort with complex circuitry arrangements. As the desired functionality increases, the circuitry becomes more intricate, significantly complicating the clothing production process and potentially compromising comfort.
The flexible silver-clad copper printed circuits developed in this study can, to a certain extent, replace traditional wires, effectively simplifying complex circuitry while enhancing clothing comfort without compromising functionality. In this study, samples prepared through single-factor experiments on printed circuits underwent washing and bending tests. Additionally, orthogonal experiments were conducted to determine the optimal printing conditions for the application of these circuits. Through single-factor experiments on thickness, line width, and quality of conductive particles, the approximate range for the orthogonal experiment was determined. After determining the approximate range, the orthogonal experiment was carried out, and three factors were selected, namely thickness, line width, and quality of conductive particles. Each factor had three levels to optimize the process conditions of the flexible printed circuit. Testing and characterization involved the use of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thickness measurements, resistance tests, bending tests, and washing tests. The resistance of the silver-coated copper printed circuit under different conditions was tested to reflect the conductivity of the printed circuit.
The results of single-factor experiments showed that the optimal conditions were with 4, 5, and 6 layers in thickness, line width of 0.7 cm, 0.8 cm and 0.9 cm, quality of conductive particles of 4.1 g, 4.25 g, and 4.4 g evenly dispersed silver-coated copper particles and 5g of transparent mortar. The uniform dispersion was used as reference to establish a three-factor three-level orthogonal experiment. The results of orthogonal experiment show that the printing circuit has good washability and bending performance under the process of printing 6 layers, namely 0.22 cm, printing line width 0.9 cm, 4.25 g conductive particles and 5 g transparent mortar quality. The sample of silver-coated copper ink printing circuit was prepared. The morphology test, elemental analysis and bending washing temperature test of the sample were carried out. It was found that the printing was uniform and the particle distribution was uniform. The sample exhibited a relatively low resistance of 1.2 Ω, the change before and after washing 10 times was 0 Ω, and the resistance changed by 0.7 Ω after 1000 bending cycles. The sample is not affected by temperature, and it remains relatively stable even at 300°C. The best process summarized provides reference for future flexible printed circuits.

Key words: washing resistance, bending resistance, silver-clad copper printing circuits, flexible printed circuits, orthogonal experiment

摘要： 为制备出性能优异的柔性银包铜印刷电路，通过单因素实验与正交实验探究优化柔性银包铜印刷电路的制备工艺。首先，通过厚度、线宽、导电颗粒含量的单因素实验来确定正交实验的水平范围，即厚度为4、5、6层；线宽为0.7、0.8、0.9 cm；导电颗粒质量为4.10、4.25、4.40 g。随后选定厚度、线宽、导电颗粒质量进行3因素3水平正交实验，探究最佳条件组合。利用扫描电镜（SEM）、能谱分析（EDS）、厚度、电阻测试以及弯折和水洗实验对印刷电路进行测试和表征。结果证明：在印刷层数为6层，即在厚度0.22 cm、线宽0.9 cm，质量4.25 g的导电颗粒与5.0 g的透明胶浆工艺条件下，印刷电路具备可机洗性和较好的耐弯折性能。研究结果可为柔性银包铜印刷电路的工艺研究提供参考价值。

关键词: 耐水洗, 耐弯折, 银包铜印刷电路, 柔性印刷电路, 正交实验