Solder joint structure and method for soldering electronic components

摘要

A method for soldering an electronic component is provided. A first solder land containing copper and a second solder land are formed on a surface of a circuit board. A first solder section composed of a Sn-Ag-Cu solder material is formed on each of the first and the second solder lands, and a terminal of an electronic component chip is mounted on the first solder land. The first solder land and the terminal are fusion-bonded. A second solder section composed of a Sn-Zn solder material is formed on the first solder section disposed on the second solder land. A lead terminal of another electronic component is inserted into a terminal hole formed near the second solder land; and the second solder section and the lead terminal are heated at a temperature lower than the temperature in step (d) to connect the lead terminal to the second solder section by fusion bonding.