摘要 |
PROBLEM TO BE SOLVED: To provide surface treatment liquid capable of obtaining excellent solderability by forming a chemical coating excellent in heat resistance and wettability with solder on the surface of copper or a copper alloy constituting a circuit part of a printed wiring board or the like, when bonding an electronic component or the like to the printed wiring board by using solder; and to provide a surface treatment method, a printed wiring board and a soldering method.SOLUTION: Surface treatment liquid of copper or a copper alloy contains an imidazole compound, iron ion and a phosphonic acid-based chelate agent. |