Ground plane for plastic encapsulated integrated circuit die packages

A plastic encapsulated integrated circuit package comprising:

• (a) a multilayer rectangular ground plane assembly consisting essentially of:
• (i) a rectangular copper metal ground plane member having a thickness ranging from about 1.5 to about 20 mils to provide both heat dissipation and an electrical ground plane for said package;
• (ii) a thermally conductive polyimide insulating layer of the same length and width as said ground plane member and having a first surface bonded to said copper ground plane member;
• and
• (iii) a b-stage epoxy layer having the same length and width as said ground plane member and having a first surface bonded to a second surface of said polyimide insulating layer;
• (b) a rectangular lead frame having inner lead ends on all four sides which terminate to define an area smaller than said rectangular ground plane assembly and a central die paddle within said area, and the peripheral portions of said inner lead ends and said die paddle bonded to a second surface of said b-stage epoxy layer of said ground plane assembly to form a composite assembly, whereby said ground plane assembly imparts mechanical strength to said lead frame assembly;
• and
• (c) an integrated circuit die bonded to an opposite surface of said die paddle on said lead frame with an electrically conductive adhesive and electrically connected to leads on said lead frame.

A plastic encapsulated integrated circuit package comprising:

• (a) a multilayer rectangular ground plane assembly consisting essentially of:
• (i) a rectangular copper metal ground plane member having a thickness ranging from about 1.5 to about 20 mils to provide both heat dissipation and an electrical ground plane for said package;
• (ii) a thermally conductive polyimide insulating layer of the same length and width as said ground plane member and having a first surface bonded to said copper ground plane member;
• and
• (iii) a b-stage epoxy layer having the same length and width as said ground plane member and having a first surface bonded to a second surface of said polyimide insulating layer;
• (b) a rectangular lead frame having inner lead ends on all four sides which terminate to define an area smaller than said rectangular ground plane assembly and the peripheral portions of said inner lead ends bonded to a second surface of said b-stage epoxy layer of said ground plane assembly to form a composite assembly, whereby said ground plane assembly imparts mechanical strength to said lead frame assembly;
• (c) a direct electrical and thermal connection between said lead frame and said copper metal ground plane member;
• and
• (d) an integrated circuit die bonded to said composite assembly with an electrically conductive adhesive and electrically connected to leads on said lead frame.

A plastic encapsulated integrated circuit package comprising:

• (a) a multilayer rectangular ground plane assembly consisting essentially of:
• (i) a rectangular copper metal ground plane member having a thickness ranging from about 1.5 to about 20 mils to provide both heat dissipation and an electrical ground plane for said package;
• (ii) a thermally conductive polyimide insulating layer of the same length and width as said ground plane member and having a first surface bonded to said copper ground plane member;
• and
• (iii) a b-stage epoxy layer having the same length and width as said ground plane member and having a first surface bonded to a second surface of said polyimide insulating layer;
• (b) a rectangular lead frame having inner lead ends on all four sides which terminate to define an area smaller than said rectangular ground plane assembly and the peripheral portions of said inner lead ends bonded to a second surface of said b-stage epoxy layer of said ground plane assembly to form a composite assembly, whereby said ground plane assembly imparts mechanical strength to said lead frame assembly;
• (c) one or more tabs on said copper metal ground plane member welded to one or more leads on said lead frame to electrically and thermally connect said leads to said ground plane member;
• and
• (d) an integrated circuit die bonded to said composite assembly with an electrically conductive adhesive and electrically connected to leads on said lead frame.