A traction battery assembly includes, among other things, a cover of a battery array, a holder attached to the cover, and a circuit board held by the holder in a position where the circuit board is spaced from the cover. The holder is configured to communicate thermal energy between the circuit board and the cover. A method of securing a circuit board of a traction battery pack includes, among other things, holding a circuit board with a holder, and attaching a holder that is holding the circuit board to a cover of a battery array. The circuit board held by the holder is held in a position where the circuit board is spaced from the cover.