Method of fabricating battery protection circuit package

A method of fabricating a battery protection circuit package, the method comprising:

• preparing a complex package substrate obtained by connecting a flexible printed circuit board (PCB) comprising at least one external connection terminal for connection to an external device, to a rigid PCB for mounting components thereon;
• mounting the complex package substrate on a lead frame comprising at least one metal tab for connection to a battery cell;
• encapsulating at least portions of the complex package substrate and the lead frame with a molded part while exposing the at least one metal tab and the at least one external connection terminal;
• further comprising attaching battery protection circuit devices onto the rigid PCB of the complex package substrate after the complex package substrate is mounted on the lead frame, and
• wherein the encapsulating comprises encapsulating the battery protection circuit devices with the molded part.