Semiconductor device including antistatic die attach material

Patent metadata

Field	Value
Publication number	US-10304795-B2
Application number	US-201715682747-A
Country	US
Kind code	B2
Filing date	Aug 22, 2017
Priority date	Mar 1, 2016
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

A semiconductor device includes a substrate, a semiconductor die, and an antistatic die attach material between the substrate and the semiconductor die. The antistatic die attach material includes a mixture of a nonconductive adhesive material and carbon black or graphite. In one example, the antistatic die attach material has a resistivity between 101 Ω·cm and 1010 Ω·cm.

First claim

The invention claimed is:

1. A semiconductor device comprising:
a semiconductor die;
a substrate comprising a conductive material;
an isolator between the substrate and the semiconductor die;
an antistatic die attach material between the substrate and the semiconductor die; and
wherein the antistatic die attach material comprises a mixture of a nonconductive adhesive material and carbon black or graphite flakes.

2. The semiconductor device of claim 1 , wherein the antistatic die attach material has a resistivity between 10 1 Ω·cm and 10 10 Ω·cm.

3. The semiconductor device of claim 1 , wherein the antistatic die attach material comprises between 1% and 10% by weight of carbon black or graphite flakes.

4. The semiconductor device of claim 1 , wherein the substrate comprises a leadframe.

5. The semiconductor device of claim 1 , wherein the nonconductive adhesive material comprises an epoxy.

6. The semiconductor device of claim 1 , wherein the antistatic die attach material comprise a die attach film.

7. The semiconductor device of claim 1 , wherein the semiconductor die comprises a magnetic field sensor to sense a current through the substrate.

8. The semiconductor device of claim 1 , wherein the isolator comprises glass, bulk silicon, or ceramic.

9. The semiconductor device of claim 1 , where the antistatic die attach material is positioned between the substrate and the isolator.

10. The semiconductor device of claim 1 , where the antistatic die attach material is positioned between the isolator and the semiconductor die.

11. The semiconductor device of claim 1 , where the antistatic die attach material is in direct contact with the isolation.

12. The semiconductor device of claim 11 , where the antistatic die attach material is positioned between the isolator and the semiconductor die.

13. A method for fabricating a semiconductor device, the method comprising:
providing a leadframe that includes a current rail and leads;
applying first antistatic material on a first substrate, wherein the first substrate comprises an isolating substrate, the first antistatic material comprising a mixture of a nonconductive adhesive material and carbon black or graphite flakes;
placing a semiconductor die on the first antistatic material;
applying second antistatic material on an upper surface of the current rail, the second antistatic material comprising a mixture of a nonconductive adhesive material and carbon black or graphite flakes;
placing the first substrate on the second antistatic material;
curing the first antistatic material and the second antistatic material; and
electrically coupling contacts on the semiconductor die to the leads via bond wires.

14. The method of claim 13 , further comprising:
mixing the nonconductive adhesive material with between 1% and 2% by weight of the carbon black or graphite flakes to provide the first antistatic material.

15. The method of claim 13 , further comprising:
mixing the nonconductive adhesive material with the carbon black or graphite flakes to provide the first antistatic material having a resistivity between 10 1 Ω·cm and 10 10 Ω·cm.

16. A semiconductor device comprising:
a substrate;
an isolator comprising an insulating material;
a semiconductor die, the semiconductor die including an electromagnetic field sensor to sense an electromagnetic field generated by a current passing through the substrate; and
an antistatic die attach material between the substrate and the semiconductor die;
wherein the antistatic die attach material comprises a mixture of a nonconductive adhesive material and carbon black or graphite flakes.

17. The semiconductor device of claim 16 , wherein the antistatic die attach material has a resistivity between 10 1 Ω·cm and 10 10 Ω·cm.

18. The semiconductor device of claim 16 , wherein the antistatic die attach material comprises between 1% and 10% by weight of carbon black or graphite flakes.

19. The semiconductor device of claim 16 , wherein the antistatic die attach material is between the substrate and the isolator.

20. The semiconductor device of claim 16 , the substrate comprising a leadframe including a current rail and a lead, where the antistatic die attach material is between the current rail and the semiconductor die, and a bond wire electrically couples the semiconductor die to the lead.

Assignees

• Infineon Technologies Ag

Inventors

• Strutz Volker
• Schaller Rainer Markus
• Kalz Franz-Peter

Classifications

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W74/127

  characterised by arrangements for sealing or adhesion · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W90/756

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

• H10W72/5363

  the connected ends being wedge-shaped · CPC title