An embodiment of the invention provides a method for forming a chip package which includes: providing a substrate having a first surface and a second surface, wherein at least one optoelectronic device is formed in the substrate; forming an insulating layer on the substrate; forming a conducting layer on the insulating layer on the substrate, wherein the conducting layer is electrically connected to the at least one optoelectronic device; and spraying a solution of light shielding material on the second surface of the substrate to form a light shielding layer on the second surface of the substrate.