Battery pack

A battery pack comprising:

• an electrode assembly comprising a positive electrode tab and a negative electrode tab;
• a circuit board comprising a positive electrode tab connector portion electrically connected to the positive electrode tab, and a negative electrode tab connector portion electrically connected to the negative electrode tab, the circuit board having a length and a width;
• and
• an anisotropic conductive film interposed between the negative electrode tab and the negative electrode tab connector portion and electrically connecting the negative electrode tab and the negative electrode tab connector portion,
• wherein the negative electrode tab connector portion comprises a reference line extending along a direction of the length of the circuit board and a plurality of auxiliary lines extending from the reference line along a direction of the width of the circuit board and spaced apart from each other,
• wherein each of the plurality of auxiliary lines comprises an auxiliary line-center line extending along the width direction and one or more protrusion patterns protruding from the auxiliary line-center line along the length direction, and
• wherein the plurality of auxiliary lines are spaced apart from each other to define a slit between adjacent ones of the plurality of auxiliary lines, and the anisotropic conductive film is disposed within the slit.