云汉芯城：公司主要业务包括电子元器件B2B销售业务和PCBA业务，下游客户数量较多且较为分散

Group 1 - The company, Yunhan Xincheng (301563.SZ), primarily engages in B2B sales of electronic components and PCBA business, with a diverse and widespread customer base across various provinces, including Hainan [2] - The company confirmed that it has customers and suppliers located in Hainan Province, indicating a broad geographical reach in its operations [2] - The company emphasized that all significant information affecting investor decisions should be based on announcements made through designated information disclosure media [2]