A semiconductor light emitting device package includes a lead frame structure including a first lead frame and a second lead frame. A resin portion is adjacent to side surfaces of the first lead frame and the second lead frame. A semiconductor light-emitting device is mounted on the first lead frame and the second lead frame, in the form of a flip chip, by eutectic bonding. Each of the first lead frame and the second lead frame has a plurality of first grooves extended in a first direction.