Leadless image sensor package structure and method for making the same

A leadless image sensor package comprising:

• a lead frame, having a die pad and a plurality of leads disposed at the periphery of the lead frame wherein the die pad has a top surface and a bottom surface and each of the leads has a wire-bonding portion, the lead frame also comprises a first surface and a corresponding second surface, step-like structures are formed at the wire-bonding portion of the leads and at the periphery of the die pad;
• a molding compound, disposed on the first surface of the lead frame and surrounding the outer edge of the lead frame, filling a clearance between the die pad and the wire-bonding portion of the leads, exposing the wire-bonding portion of the leads on the first surface, and forming a “chip containing space” by combining together with the lead frame;
• a chip, having an active surface and a corresponding back surface wherein the active surface has a plurality of bonding pads, and the chip is set in the “chip containing space” with the back surface of the chip attached to the top surface of the die pad;
• a plurality of wire, electrically connected respectively to the bonding pads and the first surface of the wire-bonding portion;
• and
• a transparent lid, disposed on the active surface to seal the “chip containing space”.