The origin and development of printed electronics

Printed electronics (Printed electronics) is an emerging industry based on printing technology, combining traditional printing technology and electronic technology to manufacture electronic products using printing means. Compared with the traditional silicon based electronic technology device processing, printed electronic technology has low energy consumption, high utilization, no corrosion, green environmental protection and other characteristics, and at the same time has a large area of large-scale manufacturing process, especially combined with Roll to Roll (roll-to-roll) preparation process, can greatly reduce production costs and improve efficiency. The reason why printed electronics is concerned by governments and research institutions is mainly for the following reasons: (1) It simplifies the traditional electronic product preparation process. Compared with the traditional circuit board preparation process, printed electronics can save the links of lithography, exposure, development, etching and film removal, which can effectively save energy consumption and materials. (2) The traditional integrated circuit is assembled by the circuit board after the assembly of electronic components, and the printed electronics will print the electronic circuit and electronic components directly, and the connection reliability is high. (3) Because printed electronics belong to thick film type electronics, organic films are the main functional materials, which are highly matched with flexible electronic technology, and have the natural properties of lightweight, bending resistance and patterning; (4) Printed electronic technology material utilization rate is high, pollution discharge is small, no chemical etching and electroplating process, is a green and environmentally friendly new technology. Of course, there are also shortcomings in printed electronics, mainly because the precision of the devices prepared by printed electronics technology is not as high as that of traditional silicon-based electronics, so the integration is greatly affected. However, the advantages of large area, flexibility and low cost of printed electronic devices and products are incomparable to silicon-based electronics.

Although the origin of printing technology has a profound history, the development of printed electronics technology is an emerging industry, which is mainly limited by the slow progress of electronic materials matching printing technology. In the 1950s, the appearance of organic conductor materials pioneered organic electronics, and organic polymers in solution brought hope for the printing of organic electronic devices. Subsequently, the scientific community began to try to process organic electronic materials by solution method and introduce printing preparation technology. Until 2000, printed OFETs devices based on inkjet printing methods appeared. Since then, with the vigorous development of nanomaterials, nano-sized inorganic curing materials have been continuously discovered and created. Various nanoparticles, nanowires, nanosheets and other materials are used in the preparation of printing inks and inks because of their unique electronic and photoelectric properties, and the performance of printed films or devices is much higher than that of organic electronic materials. Nanomaterials based on functionalization have conductive, dielectric, semiconductor or photoelectric properties, and are further applied to various semiconductor devices, photoelectric or photovoltaic devices, perfectly demonstrating the advantages of low cost, large area, and bending resistance of printed electronics technology. Since then, printed electronics has gradually taken shape and become a new discipline and technology.

In 2008, Kovio Company of the United States successfully developed flexible radio frequency tags (RFID) based on inkjet printing. In 2009, Suncheon University in South Korea used R2R printing technology to prepare RFID of carbon nanotube materials. The above two cases have become landmark events leading the development of printed electronics, indicating that the application of inorganic nanomaterials in the field of printed electronics has important potential. After 2009, academic conferences on the topic of printed electronics technology began to be held. In recent years, thanks to the reduction of sintering temperature of inorganic nanomaterials, printed electronic materials are suitable for more and more substrates, such as polyethylene terephthalate (PET), paper and so on. For example, printable low-temperature silver nanomaterial pastes or inks have been widely used in electronic circuits or electrodes in the field of printed electronics. The International Large-area Organic and Printed Electronics Conference (LOPEC) was held for the first time in Germany in 2009, whereas before that there were only research conferences related to organic electronic materials. In the same year, the first International Conference on Flexible and Printed Electronics (ICFPE) based in the Asia-Pacific region was held in South Korea. The two conferences in the same year both took printed electronics as the main topic of discussion, suggesting that the development of printed electronics technology and industry is about to accelerate. Government agencies in various countries have increased their attention to and investment in printed electronics, such as the United Kingdom and South Korea have set up national printed electronics centers. In 2011, Japan established the Japan Advanced Printed Electronics Technology Research Association (JAPERA). In 2012, the world's first international printed electronics Standards Committee was led by South Korea, affiliated to the International Electronic Commission IEC, and launched the national printed electronics development plan, with a total investment of 172.5 billion won (about 1 billion yuan). In addition, Korea has established the National Printed Electronics Association (KoPEA).

The domestic printed electronics technology started slightly later, and only a few research institutions conducted research on printed electronics before 2010. The Suzhou Institute of Nano-tech and Nano-bionics (SINANO), founded by the Chinese Academy of Sciences in 2010, opened a boom in printed electronics research in China. Subsequently, in 2011, Tianjin University and Beijing Institute of Printing jointly established the Printed Electronics Research Center. In the same year, the national Innovation Alliance of Printed Electronics (IAPE) was formed. The alliance is committed to uniting the electronic information and printing industry, as well as accelerating the development of domestic printed electronics technology, and provides a platform for cooperation and exchange for domestic research institutions and enterprises in the development of printed electronics. In 2013, Changzhou Printed Electronics Research Institute with a total investment of 8 million US dollars was established, becoming an important force in the domestic printed electronics field. Due to the rapid development of domestic printed electronic technology, The 5th International Conference on Flexible and Printed Electronics (ICFPE 2014) was successfully held in China. In the government's 13th Five-Year Plan, printed electronics also has clear project support. The above shows that the domestic printed electronics industry shows a trend of accelerated development, after several years of efforts, the level of domestic printed electronics development is basically synchronized with international development. Printed electronics is an emerging field based on the development of traditional printing technology, therefore, the traditional printing process, such as inkjet printing process, screen printing process, transfer printing process, gravure printing process, scraping process, etc., can be applied to the development and production of printed electronic products, but it is not a printing process to complete the integration of electronic technology requirements. The common use of different printing technologies is usually required, as well as the characteristics and processes of printed electronic materials