A circuit board (1) for mounting at least one light source (10), comprising a substrate (2) and a plurality of printed electrical conductors (3) printed on the substrate (2), At least one printed electrical conductor (3) comprises a first region (4) for arranging the light sources (10). The circuit board (1) further comprises reflectors (5) which are disposed between the printed electrical conductors (3) adjacent to each other and cover other regions of the printed electrical conductors (3) than the first region (4), wherein the reflectors (5) are insulating reflectors. The circuit board is easy to manufacture, has relatively high reflective property, and can efficiently reflect the light emitted from the light source. Also disclosed are a method for manufacturing the circuit board, and an illumination device comprising the circuit board.