To provide a substrate, a circuit board, and a battery pack, which prevents a metal plate and a protection circuit from short-circuiting before soldering, and inhibits malfunctions in an over voltage protection IC or the like.

Plating 7 consisting of conductive materials such as copper or the like is formed in an inside surface of an open hole 12. An island 13 is formed around an opening of the open hole 12. The island 13 is provided with a soldering island part 14 which is used as a soldered part. The soldering island part 14 consists of: a first island part 15 provided around the opening of the open hole 12; and a second island part 16 provided around the first island part 15, so as not to touch the first island part 15.

COPYRIGHT: (C)2009,JPO&INPIT