Battery pack protective circuit with external terminals on opposite side of part mounting surface of circuit board

摘要

What is proposed is a battery pack incorporating a lithium ion battery. The battery pack has: a circuit board (10A) of the type that parts are mounted on one surface thereof, on the part-mounting surface (11A) of which a plurality of circuit parts (20) forming a protective circuit (60) for preventing the over-charge and over-discharge of the battery; and resin (30A) which seals the whole part-mounting surface of the circuit board after the circuit parts have been mounted thereon. Transistors (Q1 and Q2) and ICs (IC1 and IC2) employed as the circuit parts are bear chips.