A hybrid circuit board for a battery pack, the battery pack comprising a cell frame and a plurality of battery cells arranged in one direction, each of the battery cells comprising a positive electrode terminal and a negative electrode terminal, and a plurality of busbars electrically connected to the positive electrode terminal or the negative electrode terminal of each of the battery cells, the hybrid circuit board comprising: a flexible substrate comprising a flexible material, the flexible substrate being electrically connectable to a plurality of busbars, the busbars electrically connecting a plurality of battery cells; and a rigid substrate comprising a rigid material, the rigid substrate being coupled to the flexible substrate to support the flexible substrate, wherein the flexible substrate comprises a plurality of tab connection portions (510, 520) along an edge thereof, and wherein a substrate tab is electrically connected to each of the tab connection portions (510, 520) and is electrically connectable to the busbars, wherein the plurality of tab connection portions (510, 520) comprise a plurality of first tab connection portions and a plurality of second tab connection portions, wherein the flexible substrate has a first shape portion formed at both sides of each of the first tab connection portions, the first shape portion being concavely cut inwardly from the edge of the flexible substrate, and wherein each second tab connection portion is connected to the edge of the flexible substrate by a second shape portion extending from the edge of the flexible substrate in an 'S' shape and wherein the second shape portion is integrally formed with the second tab connection portion, wherein the second shape portion comprises an extension portion extending in a straight line from one end of the edge of the flexible substrate, a curved portion integrally formed with the extension portion and having an approximately 'S' curve shape, and a connection portion formed integrally with the curved portion and formed in a straight line to be connected to the second tab connection portion. a flexible substrate comprising a flexible material, the flexible substrate being electrically connectable to a plurality of busbars, the busbars electrically connecting a plurality of battery cells; and a rigid substrate comprising a rigid material, the rigid substrate being coupled to the flexible substrate to support the flexible substrate, wherein the flexible substrate comprises a plurality of tab connection portions (510, 520) along an edge thereof, and wherein a substrate tab is electrically connected to each of the tab connection portions (510, 520) and is electrically connectable to the busbars, wherein the plurality of tab connection portions (510, 520) comprise a plurality of first tab connection portions and a plurality of second tab connection portions, wherein the flexible substrate has a first shape portion formed at both sides of each of the first tab connection portions, the first shape portion being concavely cut inwardly from the edge of the flexible substrate, and wherein each second tab connection portion is connected to the edge of the flexible substrate by a second shape portion extending from the edge of the flexible substrate in an 'S' shape and wherein the second shape portion is integrally formed with the second tab connection portion, wherein the second shape portion comprises an extension portion extending in a straight line from one end of the edge of the flexible substrate, a curved portion integrally formed with the extension portion and having an approximately 'S' curve shape, and a connection portion formed integrally with the curved portion and formed in a straight line to be connected to the second tab connection portion.