Multi-leadframe semiconductor package and method of manufacture

1. A method of manufacturing a multi-leadframe semiconductor package comprising:

providing a first leadframe having a die pad and a plurality of contact leads around the periphery of the die pad;

providing a die attached to the die pad and electrically connected to the plurality of contact leads;

providing a heat spreader leadframe having a heat spreader and a plurality of terminal leads around the periphery of the heat spreader;

attaching the die pad to the heat spreader; and

attaching the plurality of contact leads to the plurality of terminal leads.

2. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 1 , wherein:

providing the first leadframe provides a packaged integrated circuit comprising at least one of a packaged leaded integrated circuit, a packaged non-leaded integrated circuit, or a combination thereof.

3. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 1 , wherein:

attaching the die pad to the heat spreader and attaching the plurality of contact leads to the plurality of terminal leads use at least one of a eutectic solder, a high lead solder, a lead-free solder, a pre-form solder, an electrically and thermally conductive paste adhesive, an electrically and thermally conductive film adhesive, or a combination thereof.

4. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 1 , wherein:

providing the first leadframe provides a first leadframe having a finish of at least one of tin-lead solder, lead-free solder, nickel-palladium-gold alloy, and a combination thereof.

5. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 1 , wherein:

providing the first leadframe having a die pad provides a die pad having a first horizontal dimension and a first thickness; and

providing the heat spreader leadframe provides a heat spreader having a second horizontal dimension and a second thickness;

wherein the second horizontal dimension is at least equal to the first horizontal dimension and the second thickness is at least equal to the first thickness.

6. A method of manufacturing a multi-leadframe semiconductor package comprising:

providing a first leadframe having a die pad and a plurality of contact leads around the periphery of the die pad;

attaching a die to the die pad;

wire bonding the die to the plurality of contact leads;

forming an encapsulant to expose the lower surfaces of the die pad and the plurality of contact pads;

providing a heat spreader leadframe having a heat spreader and a plurality of terminal leads around the periphery of the heat spreader; and

attaching the die pad to the heat spreader.

7. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 6 , wherein:

attaching the first leadframe to the heat spreader leadframe further comprises:

attaching the die pad to the heat spreader; and

attaching the plurality of contact pads to the plurality of terminal pads.

8. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 6 , wherein:

attaching the first leadframe to the heat spreader leadframe uses at least one of a eutectic solder, a high lead solder, a lead-free solder, a pre-form solder, an electrically and thermally conductive paste adhesive, an electrically and thermally conductive film adhesive, or a combination thereof.

9. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 6 , wherein:

providing the first leadframe provides a first leadframe having a finish of at least one of tin-lead solder, lead-free solder, nickel-palladium-gold alloy, and a combination thereof.

10. The method of manufacturing a multi-leadframe semiconductor package as claimed in claim 6 , wherein:

providing the first leadframe having a die pad provides a die pad having a first horizontal dimension and a first thickness; and

attaching the first leadframe to the heat spreader leadframe attaches the die pad to a heat spreader having a second horizontal dimension and a second thickness;

wherein the second horizontal dimension is at least equal to the first horizontal dimension and the second thickness is at least equal to the first thickness.

11. A multi-leadframe semiconductor package comprising:

a first leadframe having a die pad and a plurality of contact leads around the periphery of the die pad;

a die attached to the die pad;

a heat spreader leadframe having a heat spreader and a plurality of terminal leads around the periphery of the heat spreader; and

means for attaching the die pad to the heat spreader.

12. The multi-leadframe semiconductor package as claimed in claim 11 , wherein:

the first leadframe further comprises a packaged integrated circuit of at least one of a packaged leaded integrated circuit, a packaged non-leaded integrated circuit, or a combination thereof.

13. The multi-leadframe semiconductor package as claimed in claim 11 , wherein:

the means for attaching the first leadframe to the heat spreader leadframe comprises at least one of a eutectic solder, a high lead solder, a lead-free solder, a pre-form solder, an electrically and thermally conductive paste adhesive, an electrically and thermally conductive film adhesive, or a combination thereof.

14. The multi-leadframe semiconductor package as claimed in claim 11 , wherein:

the first leadframe has a finish of at least one of tin-lead solder, lead-free solder, nickel-palladium-gold alloy, and a combination thereof.

15. The multi-leadframe semiconductor package as claimed in claim 11 , wherein:

the first leadframe comprises a die pad having a first horizontal dimension and a first thickness; and

the heat spreader leadframe comprises a heat spreader having a second horizontal dimension and a second thickness;

wherein the second horizontal dimension is at least equal to the first horizontal dimension and the second thickness is at least equal to the first thickness.

16. A multi-leadframe semiconductor package comprising:

a first leadframe having a die pad and a plurality of contact leads around the periphery of the die pad;

a die attached to the die pad;

bond wires electrically connecting the die to the plurality of contact leads;

an encapsulant to expose the lower surfaces of the die pad and the plurality of contact pads;

a heat spreader leadframe having a heat spreader and a plurality of terminal leads around the periphery of the heat spreader; and

means for attaching the die pad to the heat spreader.

17. The multi-leadframe semiconductor package as claimed in claim 16 , wherein:

the die pad is attached to the heat spreader; and

the plurality of contact pads is attached to the plurality of terminal pads.

18. The multi-leadframe semiconductor package as claimed in claim 16 , wherein:

the means for attaching the first leadframe to the heat spreader leadframe comprises at least one of a eutectic solder, a high lead solder, a lead-free solder, a pre-form solder, an electrically and thermally conductive paste adhesive, an electrically and thermally conductive film adhesive, or a combination thereof.

19. The multi-leadframe semiconductor package as claimed in claim 16 , wherein:

the first leadframe has a finish of at least one of tin-lead solder, lead-free solder, nickel-palladium-gold alloy, and a combination thereof.

20. The multi-leadframe semiconductor package as claimed in claim 16 , wherein:

the die pad has a first horizontal dimension and a first thickness; and

the heat spreader has a second horizontal dimension and a second thickness;

wherein the second horizontal dimension is at least equal to the first horizontal dimension and the second thickness is at least equal to the first thickness.