Method for roller-coating liquid material

A method for roller-coating a liquid material, comprising roller-coating the liquid material on a silicon wafer with a liquid coating roller, and controlling a thickness of the liquid material carried on the liquid coating roller with a liquid taking roller, wherein a liquid retaining structure is provided at two ends of the liquid coating roller and/or two ends of the liquid taking roller, and the liquid retaining structure is configured to prevent the liquid material from flowing out from the two ends of the liquid coating roller and the two ends of the liquid taking roller;

• the liquid retaining structure comprises a pair of annular recessed grooves and a pair of liquid retaining raised rings, wherein the pair of annular recessed grooves are respectively provided at two ends of an outer circumferential surface of the liquid coating roller, and the pair of liquid retaining raised rings are respectively provided at two ends of an outer circumferential surface of the liquid taking roller;
• and the pair of annular recessed grooves are arranged to respectively correspond to the pair of liquid retaining raised rings, the pair of annular recessed grooves are configured to accommodate the pair of liquid retaining raised rings, respectively, and the pair of liquid retaining raised rings are configured to be embedded into the pair of annular recessed grooves, respectively;
• and
• the pair of annular recessed grooves are allowed to be in contact with the silicon wafer, and the pair of annular recessed grooves each form a stripe-like trace on the silicon wafer;
• and a width of the stripe-like trace is measured to determine a depression of the liquid coating roller according to the width of the stripe-like trace, and a pressure applied by the liquid coating roller to the silicon wafer is determined according to the depression of the liquid coating roller.