Method for fabricating stack die package

Patent metadata

Field	Value
Publication number	US-9589929-B2
Application number	US-201313830041-A
Country	US
Kind code	B2
Filing date	Mar 14, 2013
Priority date	Mar 14, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

In one embodiment, a method can include coupling a gate and a source of a first die to a lead frame. The first die can include the gate and the source that are located on a first surface of the first die and a drain that is located on a second surface of the first die that is opposite the first surface. In addition, the method can include coupling a source of a second die to the drain of the first die. The second die can include a gate and a drain that are located on a first surface of the second die and the source that is located on a second surface of the second die that is opposite the first surface.

First claim

What is claimed is:

1. A method comprising:
attaching a gate and a source of a first die to a lead frame, said first die comprising said gate and said source that are located on a first surface of said first die and a drain that is located on a second surface of said first die that is opposite said first surface;
coupling a source of a second die to said drain of said first die, said second die comprising a gate and a drain that are located on a first surface of said second die and said source that is located on a second surface of said second die that is opposite said first surface;
attaching a clip to said lead frame and said drain of said second die, said clip comprising a first platform, a second platform, and a sloped portion located between said first platform and said second platform, said first platform is located above said second platform;
performing a molding process comprising covering said first die, second die, and clip with a molding material, said molding process comprises using a flexible film so a portion of an upper surface of said clip is free of said molding material, said molding process further comprises using a molding tool comprising a mold surface capable of contacting said upper surface of said clip; and
preventing said portion of said upper surface of said clip from being plated during a plating process, said portion of said upper surface of said clip is exposed in final package.

2. The method of claim 1 , further comprising:
coupling said lead frame and said gate of said second die.

3. The method of claim 1 , wherein said attaching said clip occurs after said coupling said source of said second die.

4. The method of claim 1 , wherein said first die comprising trench gate technology.

5. The method of claim 1 , further comprising:
coupling a second clip to said lead frame, said drain of said first die, and to said source of said second die.

6. The method of claim 5 , further comprising:
coupling a third clip to said lead frame and said gate of said second die.

7. The method of claim 5 , wherein said attaching said clip occurs after said coupling said second clip.

8. The method of claim 6 , wherein said attaching said clip occurs at the same time as said coupling said third clip.

9. A method comprising:
attaching a gate and a source of a first die to a lead frame with solder paste, said first die comprising said gate and said source that are located on a first surface of said first die and a drain that is located on a second surface of said first die that is opposite said first surface, said first die comprising split gate technology;
coupling a source of a second die to said drain of said first die, said second die comprising a gate and a drain that are located on a first surface of said second die and said source that is located on a second surface of said second die that is opposite said first surface;
attaching a clip to said lead frame and said drain of said second die with solder paste, said clip comprising a first platform, a second platform, and a sloped portion located between said first platform and said second platform said first platform is located above said second platform;
performing a molding process comprising covering said first die, second die, and clip with a molding material, said molding process comprises using a flexible film so a portion of an upper surface of said clip is free of said molding material, said molding process further comprises using a molding tool comprising a mold surface capable of contacting said upper surface of said clip; and
preventing said portion of said upper surface of said clip from being plated during a plating process, said portion of said upper surface of said clip is exposed in final package.

10. The method of claim 9 , wherein said attaching said clip occurs after said coupling said source of said second die.

11. The method of claim 9 , further comprising:
coupling said lead frame and said gate of said second die.

12. The method of Claim 9 , further comprising:
before said preventing, coupling a second clip to said lead frame and said gate of said second die.

13. The method of claim 9 , wherein said clip comprises an electrically conductive material.

14. The method of claim 9 , further comprising:
coupling a second clip to said lead frame, said drain of said first die, and to said source of said second die.

15. The method of claim 9 , wherein said preventing comprises using a film.

16. A method comprising:
attaching a gate and a source of a first die to a lead frame with conductive adhesive, said first die comprising said gate and said source that are located on a first surface of said first die and a drain that is located on a second surface of said first die that is opposite said first surface, said first die comprising split gate technology;
coupling a source of a second die to said drain of said first die, said second die comprising a gate and a drain that are located on a first surface of said second die and said source that is located on a second surface of said second die that is opposite said first surface;
attaching a clip to said lead frame and said drain of said second die with conductive adhesive, said clip comprising a first platform, a second platform, and a sloped portion located between said first platform and said second platform, said first platform is located above said second platform;
performing a molding process comprising covering said first die, second die, and clip with a molding material, said molding process comprises using a flexible film so a portion of an upper surface of said clip is free of said molding material, said molding process further comprises using a molding tool comprising a mold surface capable of contacting said upper surface of said clip; and
preventing said portion of said upper surface of said clip from being plated during a plating process, said portion of said upper surface of said clip is exposed in final package.

17. The method of claim 16 , wherein said attaching said clip occurs of said coupling said source of said second die.

18. The method of claim 16 , coupling a second clip to said lead frame and said gate of said second die.

19. The method of claim 18 , wherein said clip and said second clip each comprises an electrically conductive material.

20. The method of claim 16 , further comprising:
coupling a second clip to said lead frame, said drain of said first die, and to said source of said second die.

Assignees

• Vishay Siliconix

Inventors

• Terrill Kyle
• Kuo Frank
• Mao Sen

Classifications

• H10W90/766

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/736

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/07654

  changes in dispositions · CPC title