Protective circuit board and battery pack using the same

A battery pack, comprising:

• a bare cell including a cap plate, an electrode terminal, a first broad side surface, and a second broad side surface facing away from the first broad side surface;
• a case configured to accommodate the bare cell therein;
• and
• a protective circuit board comprising a flexible printed circuit board as a separate piece from the case, wherein the flexible printed circuit board comprises a first region, a second region, and a third region, the first region being located between the second and third regions, the protective circuit board further comprising:
• a protection module, a PTC thermistor, and first and second power terminals that are mounted on the first region, wherein the first region is folded relative to the second and third regions, such that the first region is placed on the cap plate, that the second region is inserted between the first broad side surface and a wall of the case, and that the third region is inserted between the second broad side surface and another wall of the case.