In the 1980s and 1990s, FPC has been used in the Yangtze River Delta region of China Production of calendered copper foil Enterprise, but its scale is very small Calendered copper foil With the growth of market demand, as of 2020, there are more than 10 calendered copper foil production enterprises in the world, mainly in Japan and the United States. In China, five calendered copper foil enterprises have been put into production, and one is under construction. Most of the production equipment is based on the introduction. It is difficult to master the rolling copper foil production process, and the level of production equipment is very high. In particular, the core technology of ultra-thin copper foil is basically in the hands of a limited number of foreign enterprises. However, due to the high added value of rolling copper foil products and considerable profits, it has become a hot product for domestic copper industry investment in recent years. according to According to statistics, in 2016, the capacity of the national calendering copper foil production enterprises reached 13120t, and the output was 3579t, breaking through the market scale of thousands of tons for the first time. Optical foil and surface treatment foil accounted for 50% respectively, and the output increased nearly 12 times compared with 2015. Due to the large scale of investment in calendering copper foil projects, domestic enterprises cannot fully grasp the core technology patents and key technologies, product research and development and market development are still in the exploratory stage, and few enterprises actually invest in the production of calendering copper foil. Considering that some of these projects are phased construction, and some projects may not be truly implemented, If 50% of the capacity listed in the table can be completed and put into production in 2020, then the domestic calendered copper foil capacity will be nearly 23120t.