Method for fabricating stack die package

Patent metadata

Field	Value
Publication number	US-10546840-B2
Application number	US-201715439817-A
Country	US
Kind code	B2
Filing date	Feb 22, 2017
Priority date	Mar 14, 2013
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

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 the source that are located on a first surface of the second die and a drain 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:
coupling 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, said first die comprising trench gate technology;
coupling a source of a second die to said drain of said first die, said second die comprising a gate and said source that are located on a first surface of said second die and a drain that is located on a second surface of said second die that is opposite said first surface;
coupling a first clip to said lead frame and said drain of said second die;
coupling a second clip to said lead frame and said gate of said second die, said second clip comprising a first platform and a second platform, said first platform coupled to said gate of said second die and said second platform overlaps a portion of said lead frame coupled to said source of said first die;
performing a molding process comprising covering said first die, second die, first clip, and second clip with a molding material, said molding process comprises using a flexible film so a portion of an upper surface of said first 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 first clip; and
using a film to prevent said portion of said upper surface of said first clip from being plated during a plating process, said portion of said upper surface of said first clip is exposed in final package.

2. The method of claim 1 , wherein said coupling said second clip to said lead frame and said gate of said second die comprises using conductive epoxy.

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

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

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

7. The method of claim 5 , wherein a portion of said third clip is located between said first die and said second die.

8. The method of claim 1 , wherein said coupling said gate and said source of said first die to said lead frame comprises using conductive epoxy.

9. A method comprising:
coupling 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 said source that are located on a first surface of said second die and a drain that is located on a second surface of said second die that is opposite said first surface;
coupling a first clip to said lead frame and said drain of said second die with solder paste;
coupling a second clip to said lead frame and said gate of said second die, said second clip comprising a first platform and a second platform, said first platform coupled to said gate of said second die and said second platform overlaps a portion of said lead frame coupled to said source of said first die;
performing a molding process comprising covering said first die, second die, first clip, and second clip with a molding material, said molding process comprises using a flexible film so a portion of an upper surface of said first 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 first clip; and
using a film to prevent said portion of said upper surface of said first clip from being plated during a plating process, said portion of said upper surface of said first clip is exposed in final package.

10. The method of claim 9 , wherein said coupling said second clip to said lead frame and said gate of said second die comprises using solder paste.

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

12. The method of claim 11 , further comprising:
coupling said source of said second die to said third clip.

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

14. The method of claim 9 , wherein said second die comprises trench gate technology.

15. A method comprising:
coupling 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, said first die comprising split gate technology;
coupling a first clip to said lead frame and said drain of said first die;
coupling a second clip to said lead frame;
coupling a source of a second die to said first clip;
coupling a gate of said second die to said second clip, said second die comprising said gate and said source that are located on a first surface of said second die and a drain that is located on a second surface of said second die that is opposite said first surface, said second die comprising split gate technology, said second clip comprising a first platform and a second platform, said first platform coupled to said gate of said second die and said second platform overlaps a portion of said lead frame coupled to said source of said first die;
coupling a third clip to said lead frame and said drain of said second die;
performing a molding process comprising covering said first die, second die, first clip, second clip, and third clip with a molding material, said molding process comprises using a flexible film so a portion of an upper surface of said third 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 third clip; and
using a film to prevent said portion of said upper surface of said third clip from being plated during a plating process, said portion of said upper surface of said third clip is exposed in final package.

16. The method of claim 15 , wherein said coupling said third clip to said lead frame and said drain of said second die comprises using conductive epoxy.

17. The method of claim 15 , wherein a portion of said first clip is located between said first die and said second die.

18. The method of claim 15 , wherein said first clip, second clip, and third clip each comprises an electrically conductive material.

19. The method of claim 15 , wherein said coupling said gate and said source of said first die to said lead frame comprises using solder paste.

20. The method of claim 15 , wherein said coupling said gate and said source of said first die to said lead frame comprises using conductive adhesive.

Assignees

• Vishay Siliconix
• Vishay Siliconix Llc

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