Dual-sided substate integrated circuit package including a leadframe having leads with increased thickness

Abstract

An integrated circuit package includes a first non-conductive substrate having a first inner surface and a second non-conductive substrate having a second inner surface. A die having a first thickness is disposed between the first and second inner surfaces. A leadframe includes a member having a proximal end and a distal end. The proximal end has a second thickness less than the first thickness. The distal end is disposed between the first and second inner surfaces. The distal end is undulated such that the distal end has an effective thickness greater than the second thickness.

1 . A method of manufacturing a lead frame, comprising:
 forming a body portion and a plurality of members extending from said body portion, each of said members having a proximal end and a distal end; and   forming an undulation in each of said distal ends.   
   
   
       2 . The method of  claim 1 , wherein said forming step includes providing each of said distal ends with an effective height substantially matching a second thickness of a die in an integrated circuit package in which said distal ends are to be inserted. 
   
   
       3 . The method of  claim 1 , wherein both of said forming steps is performed with a progressive die. 
   
   
       4 . The method of  claim 1 , wherein said distal end is one of offset formed, squirt formed, corrugated formed, and embossed formed. 
   
   
       5 . The method of  claim 1 , comprising the further step of bending each of said members at an angle of approximately 90° such that said distal ends of said members extend in a direction substantially perpendicular to said body. 
   
   
       6 . The method of  claim 1 , wherein said plurality of members define a plane, each of said members being nonlinear in a direction within said plane. 
   
   
       7 . The method of  claim 1 , wherein said step of forming an undulation includes punching each of said distal ends. 
   
   
       8 . A lead frame adapted for use within an integrated circuit package of the type including:
 a first non-conductive substrate having a first inner surface,   at least one first contact pad disposed on said first inner surface for selective electrical communication with circuit elements through conductors carried by said first substrate,   a second non-conductive substrate having a second inner surface,   at least one second contact pad disposed on said second inner surface for selective electrical communication with circuit elements through conductors carried by said second substrate, wherein said first and second contact pads are opposed from one another, and   a die disposed between said first and second inner surfaces, said die having a first thickness,   
     said lead frame comprising:
 a body portion; and 
 a plurality of members extending from said body portion, each said member having a proximal end and a distal end, said proximal end having a first thickness, said distal end being undulated such that said distal end has an effective thickness greater than said first thickness. 
 
   
   
       9 . A method of manufacturing a lead frame, comprising the steps of:
 forming a body portion; and   forming a plurality of members extending from said body portion, each of said members defining a proximal end and a distal end, with each of said proximal ends having a first thickness, and   forming an undulation in each of said distal ends, whereby each said distal end has an effective thickness greater than said first thickness,   wherein each distal end defines opposed surfaces for simultaneously bridging facing contact surfaces which are separated by a dimension greater than said first thickness.   
   
   
       10 . A lead frame, comprising:
 a body portion; and   a plurality of members extending from said body portion, each said member having a proximal end and a distal end, said proximal end having a first thickness, said distal end being undulated such that said distal end has an effective thickness greater than said first thickness, wherein said distal end is squirt formed.   
   
   
       11 . A lead frame, comprising:
 a body portion; and   a plurality of members extending from said body portion, each said member having a proximal end and a distal end, said proximal end having a first thickness, said distal end being undulated such that said distal end has an effective thickness greater than said first thickness, wherein said distal end is embossed formed.