(1) China's EL cold light film industry has developed since the 1990s. After nearly 30 years of technological accumulation and market cultivation, it has gradually become an important branch in the field of semiconductor lighting. According to the latest data, the market size of my country's EL cold light films exceeded 10 billion yuan in 2019, an increase of about 20% year-on-year. With the continuous expansion of the domestic LED lighting market, the application fields of EL cold light sheets are also constantly expanding, including indoor lighting, outdoor lighting, display screens and backlight sources. Especially the widespread application in the fields of consumer electronic products such as smartphones and tablets has promoted the rapid growth of the EL cold light film industry.