Method of forming stacked die package
A method of packaging semiconductor integrated circuits, including the steps of providing a transfer film and forming a patterned, conductive layer on a surface of the transfer film. A first semiconductor integrated circuit (IC) then is attached to the transfer film, where an active side of the first IC is attached to the transfer film. A second semiconductor IC then is attached to the first IC, where a bottom side of the second IC is attached to a bottom side of the first IC. Die pads on an active surface of the second IC are electrically connected to the conductive layer with wires and then a resin material is provided on one side of the transfer film to encapsulate the first and second ICs, the wires and a portion of the conductive layer. Next the transfer film is removed, which exposes the active side of the first IC and the conductive layer. An electrical distribution layer is formed over the active side of the first IC and the conductive layer and conductive balls are attached to the electrical distribution layer. The conductive balls allow electrical interconnection to the first and second integrated circuits.
1. A method of packaging semiconductor integrated circuits, comprising the steps of:
providing a transfer film;
forming a patterned, conductive layer on a surface of the transfer film via a photolithography process;
attaching a first semiconductor integrated circuit (IC) to the transfer film, wherein an active side of the first IC is attached to the transfer film;
attaching a second semiconductor IC to the first IC, wherein a bottom side of the second IC is attached to a bottom side of the first IC;
electrically connecting die pads on an active surface of the second IC to the conductive layer with wires;
providing a resin material on one side of the transfer film to encapsulate the first and second ICs, the wires and a portion of the conductive layer;
removing the transfer film, thereby exposing the active side of the first IC and the conductive layer;
forming an electrical distribution layer over the active side of the first IC and the conductive layer; and
attaching conductive balls to the electrical distribution layer, wherein the conductive balls allow electrical interconnection to the first and second integrated circuits.
2. The method of packaging semiconductor integrated circuits of claim 1 , wherein the transfer film comprises a polyimide tape.
3. The method of packaging semiconductor integrated circuits of claim 1 , wherein the conductive layer comprises copper.
4. The method of packaging semiconductor integrated circuits of claim 1 , wherein the transfer film has an adhesive thereon and the first IC is attached to the transfer film with the adhesive.
5. The method of packaging semiconductor integrated circuits of claim 1 , wherein the step of attaching the first IC to the second IC includes attaching with one of an epoxy and an adhesive tape.
6. A method of packaging a semiconductor integrated circuit of claim 1 , wherein the step of forming a patterned, conductive layer on a surface of the transfer film comprises:
forming a dry film layer on a surface of the transfer film; forming a pattern in the dry film layer;
depositing a conductive metal layer in the patterned dry film layer; and
stripping the dry film layer.
7. The method of packaging a semiconductor integrated circuit of claim 1 , wherein the step of forming an electrical distribution layer over the active side of the first IC and the conductive layer includes a photolithography process.
8. The method of packaging a semiconductor integrated circuit of claim 7 , wherein the step of forming an electrical distribution layer over the active side of the first IC and the conductive layer further includes a plating process.
9. A method of packaging semiconductor integrated circuits, comprising the steps of:
providing a transfer film;
forming a dry film layer on a surface of the transfer film;
forming a pattern in the dry film layer;
depositing a conductive metal layer in the patterned dry film layer;
stripping the dry film layer, thereby leaving a patterned conductive layer on a surface of the transfer film
attaching a first semiconductor integrated circuit (IC) to the transfer film, wherein an active side of the first IC is attached to the transfer film;
attaching a second semiconductor IC to the first IC, wherein a bottom side of the second IC is attached to a bottom side of the first IC;
electrically connecting die pads on an active surface of the second IC to the conductive layer with wires;
providing a resin material on one side of the transfer film to encapsulate the first and second ICs, the wires and a portion of the conductive layer;
removing the transfer film, thereby exposing the active side of the first IC and the conductive layer;
forming an electrical distribution layer over the active side of the first IC and the conductive layer; and
attaching conductive balls to the electrical distribution layer, wherein the conductive balls allow electrical interconnection to the first and second integrated circuits.
10. The method of packaging semiconductor integrated circuits of claim 9 , wherein the transfer film comprises a polyimide tape.
11. The method of packaging semiconductor integrated circuits of claim 9 , wherein the step of forming a pattern in the dry film layer comprises a photolithography process.
12. The method of packaging semiconductor integrated circuits of claim 9 , wherein the conductive metal comprises copper.
13. The method of packaging semiconductor integrated circuits of claim 9 , wherein the transfer film has an adhesive thereon and the first IC is attached to the transfer film with the adhesive.
14. The method of packaging semiconductor integrated circuits of claim 9 , wherein the step of attaching the first IC to the second IC includes attaching with one of an epoxy and an adhesive tape.
15. The method of packaging a semiconductor integrated circuit of claim 9 , wherein the step of forming an electrical distribution layer over the active side of the first IC and the conductive layer includes a photolithography process and a plating process.
16. A semiconductor device formed according to the method of claim 9 .