Integrated circuit packaging system with interlock and method of manufacture thereof

A method of manufacture of an integrated circuit packaging system comprising:

• forming a lead having a lead top side, a bottom side, a lead overhang and a lead ridge, the lead overhang having a non-horizontal side, an overhang-undercut side and the overhang non-horizontal side being at an obtuse angle to the lead top side, the overhang-undercut side being at an acute angle to the overhang non-horizontal side, and the overhang non-horizontal side and the overhang-undercut side forming an apex at the ends thereof;
• the lead ridge protruding from the lead bottom side and having upper and lower concave surfaces;
• the lead having a width continuously increasing from the lead top side to the apex and continuously decreasing from the apex to the upper concave surface of the ridge;
• forming a lead conductive cap completely covering the lead top side and the lead overhang non-horizontal side, without covering the lead overhang-undercut side and the concave surfaces of the ridge;
• forming a package paddle having a top side and a bottom side adjacent the lead;
• mounting an integrated circuit over the top side of the package paddle;
• attaching an electrical connector to the integrated circuit and the lead conductive cap;
• and
• forming an encapsulation over the integrated circuit and partially over the package paddle and the lead exposing the bottom sides of the package paddle and the lead.