Circuit board and production method therefor

摘要

A lead frame of a circuit board is punched in a direction opposite to a heat sink plate. Even if burrs are produced due to the punching, the burrs do not penetrate a sheet or short-circuit to the heat sink plate. A resist film tightly contacts on the periphery of a land of the lead frame of the circuit board, and a plated layer tightly contacts on the land. This prevents electronic components from defective mounting on the land.