Manufacturing method of molded image sensor packaging structure with predetermined focal length and the structure using the same

A manufacturing method of a molded image sensor packaging structure, the manufacturing method comprising steps of:

• providing a substrate, wherein the substrate comprises a bearing surface and a bottom surface, and the bearing surface is formed with a plurality of first conductive contacts;
• providing a chip, wherein the chip comprises a first surface bonded to the bearing surface, a second surface having a sensing area, and a plurality of second conductive contacts arranged around the sensing area and each electrically connected to a respective said first conductive contact through a metal leading wire;
• providing a lens module, wherein the lens module is set on the second surface over the sensing area so as to form an air chamber above the sensing area, and has a predetermined focal length, in which the substrate, the chip and the lens module form a semi-finished component;
• providing a mold, wherein the mold comprises an upper mold member and a lower mold member, and the upper mold member is provided with a buffer layer;
• positioning the semi-finished component into the mold to form a mold cavity between the semi-finished component and the mold, wherein the buffer layer abuts against an upper surface of the lens module and the lower mold member abuts against the bottom surface of the substrate;
• injecting a molding compound into the mold cavity, so as to make the molding compound cover the periphery of the semi-finished component but leave the upper surface of the lens module uncovered;
• and
• after transfer molding the molding compound, opening the mold and performing a post mold cure process to cure the molding compound.