BATTERY PACK AND METHOD OF PRODUCING THE SAME

摘要

A protective circuit unit (52) is a composite body constructed by mounting a plane-mount type PTC thermistor (49) together with a protective IC (45) and FET unit (46) on a printed circuit board (44) by soldering, such as reflow soldering. The plane-mount type PTC thermistor (49), unlike a lead-equipped PTC thermistor, makes it unnecessary to form a circuit by connecting the lead terminal to the negative terminal or printed circuit board of a square element battery (41) by bending or electric welding, and can be mounted on the printed circuit board (44). As a result, variations in resistance value caused as by bending stress or high-temperature heat stress can be eliminated. And, the degree of thermal bonding to the element battery (41) can be adjusted by the arrangement of the thermistor (49), making a variety of control functions possible.