Research On The Technologies And Key Materials Of Green Printing Electronics

The conventional copper etching technology is known as complex, energy intensive, high cost and environmentally hazardous. Of which the environmental problems in the fabrication process as well as in the recycling process have been a global challenge since long. This is a tough challenge because the main problems are all related to the conventional subtraction technique which is inevitable. Towards this, the printing electronics technology which is an additive one has attracted more and more attentions in recent years, and there have been many researches and applications about the printing techniques and materials. However, in the application of printed circuits boards(PCB), especially multiple layered PCB, there are still many issues to be solve, such as high performance printing conductive materials and the interlayer electrical connection technique.In this paper, a technical route was proposed to fabricate paper based multiple layered printed circuits board(PPCB), which was based on the research on the high performance silver conductive adhesive and screen printing technique. By solving the interlayer electrical connection problem, multiple layered PPCB(the maximum can be 10 layers) was successfully fabricated. By testing the performances of the as prepared PPCB, the comprehensive properties were proved to meet the basic demands of the International Printed Circuits(IPC) standards of the PCB industry. Meanwhile, the properties which still need to be improved in the future development of paper printing electronics technology were also figured out. What’s more, a life cycle assessment(LCA) study of PPCB was conducted for the first time to quantificationally evaluate the environmental impacts of the life cycle of PPCB. By a comparison LCA study, it was proved that the environmental impacts of PPCB were 2 magnitudes smaller than the conventional technique. Thus, in the research of this paper, the fabrication technology, performance and environmental impacts of PPCB were investigated, through the fabrication and tests of the electronic devices based on PPCB, it was demonstrated that the PPCB technology was promising in application of the low-frequency, low-density, low-cost and short lifetime electronic devices.On the other side, towards the limitation of silver conductive paste in the application of high-frequency and high-density electrical circuits, a Zn seed paste based on epoxy resin and the related technique which was based on a replacement deposition reaction were developed in this paper to fabricate high performance copper conductive circuits. By adjusting the formula of the Zn seed paste and the Cu2+ solution, Cu circuits with bulk Cu conductivity was fabricated which also had good mechanical property and reliable performance. By fabricating flexible circuits, 3D antenna and RFID tags with Cu conductive circuits, it was demonstrated that the high performance Cu circuits can be used in the high frequency and high density electrical circuits.