Electro-mechanical heat sink gasket for shock and vibration protection and EMI suppression on an exposed die

• US 6,390,475 B1
• Filed: 08/31/1999
• Issued: 05/21/2002
• Est. Priority Date: 08/31/1999
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Aoki, Russell S., Zhao, Richard, Cooks, Correy D., Chiu, Chia-Pin, Eckblad, Michael Z.
• Primary Examiner(s): Knight, Anthony
• Assistant Examiner(s): PATEL, VISHAL A
• Application Number:
  US09/387,048
• Time in Patent Office: 994 Days
• Field of Search: 277/628, 277/650, 277/915, 277/919, 277/312, 277/315, 277/316, 165/185, 165/80.3, 361/704, 361/705, 257/713, 257/719, 257/720
• US Class Current: 277/312
• CPC Class Codes: F16J 15/064 the packing combining the sealing function with other functions
• CPC Class Codes: H01L 23/4093 Snap-on arrangements, e.g. clips
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/562 Protection against mechanical damage H01L23/02, H01L23/28 take precedence
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 9/0015 Gaskets or seals
• CPC Class Codes: Y10S 277/915 Seal including compression set feature
• CPC Class Codes: Y10S 277/919 Seal including electrical feature

Abstract

A method and assembly for utilizing a gasket to protect an exposed die from damage, such as chipping and cracking, caused by external forces such as shock, vibrations, installation and/or handling, as well as to prevent electromagnetic interference (EMI) emissions from the exposed die.

Claims

1. A method for protecting an exposed die mounted on a substrate surface from structural damage caused by external forces, said method comprising the steps of:

placing a gasket on said substrate surface, wherein said gasket has an opening which fits over said exposed die, and wherein said gasket has a greater height than said exposed die when said gasket is in a non-compressed state;

concurrently or subsequently to said placing of said gasket, placing a die reference heat sink over said gasket and said exposed die such that said heat sink is not in contact with said exposed die; and

compressing said gasket with said die reference heat sink to reduce the height of said gasket until a bottom surface of said heat sink contacts with a top surface of said exposed die.

2. A method according to claim 1, wherein said gasket is adhered to a bottom surface of said heat sink.

3. A method according to claim 1, wherein said gasket assists in absorbing any shocks and vibrations applied to said exposed die.

4. A method according to claim 1, wherein said gasket is made of a material having bi-linear stiffness, wherein an amount of force for compressing the gasket a unit distance changes to a higher value after the gasket has been compressed to substantially equal the height of the exposed die by the heat sink.

5. A method according to claim 1, wherein said gasket is at least partially made of an electrically conductive material.

6. A method according to claim 5, wherein said gasket and said heat sink, in combination with a ground ring in said substrate surface, provide a barrier surrounding-said exposed die to eliminate electromagnetic interference (EMI) emissions from said exposed die.

7. A heat sink-gasket assembly, comprising:

a die reference heat sink;

a gasket;

an exposed die mounted on a substrate surface;

wherein said gasket has a central opening to fit over said exposed die on said substrate surface such that said gasket has a height greater than said exposed die when said gasket is in a non-compressed state; and

wherein said gasket is compressed by said heat sink from a position where the heat sink is out of contact with said exposed die to a position reducing the height of said gasket until said heat sink contacts with a top surface of said exposed die.

8. A heat sink-gasket assembly according to claim 7, wherein said gasket is adhered to a bottom surface of said heat sink.

9. A heat-sink assembly according to claim 7, wherein said gasket assists in attenuating any shocks and vibrations applied to said exposed die.

10. A heat sink-gasket assembly according to claim 7, wherein said gasket is made of a material having bi-linear stiffness, wherein an amount of force for compressing the gasket a unit distance changes to a higher value after the gasket has been compressed to substantially equal the height of the exposed die by the heat sink.

11. A heat sink-gasket assembly according to claim 7, wherein said gasket is at least partially made of an electrically conductive material.

12. A heat sink-gasket assembly according to claim 11, wherein said gasket and said heat sink, in combination with a ground ring or ground points in said substrate surface, provide a barrier surrounding said exposed die to eliminate electromagnetic interference (EMI) emissions from said exposed die.

13. An electromagnetic interference emissions suppressing system for an exposed die, comprising:

a substrate surface upon which said exposed die is placed;

a gasket having an opening which fits over said exposed die, said gasket having a greater height that that of said exposed die in a non-compressed state;

a die reference heat sink; and

wherein said gasket in combination with said substrate surface and said heat sink, forms a barrier to suppress electromagnetic interference (EMI) emissions from said exposed die, and

wherein said gasket is compressed by said heat sink from a position where the heat sink is out of contact with said exposed die to a position reducing the height of said gasket until said heat sink contacts with a top surface of said exposed die.

14. A system according to claim 13, wherein said gasket is at least partially made of an electrically conductive material.

15. A system according to claim 13, wherein said gasket is compressed between said substrate surface and said heat sink until said heat sink contacts with said exposed die.

16. A system according to claim 13, wherein said gasket is attached to a bottom surface of said heat sink.

17. A system according to claim 13, wherein said gasket assists in absorbing any shocks and vibrations applied to said exposed die.

18. A system according to claim 13, wherein said gasket has bi-linear stiffness, wherein an amount of force for compressing the gasket a unit distance changes to a higher value after the gasket has been compressed to substantially equal the height of the exposed die by the heat sink.

19. A method for reducing EMI emissions from an exposed die mounted on a substrate surface, said method comprising the steps of:

placing a gasket on said substrate surface, said gasket having an opening which fits over said exposed die, and said gasket having a greater height than that of said exposed die when said gasket is in a non-compressed state;

concurrently or subsequently to said placing of said gasket, placing a die reference heat sink over said gasket and said die such that said heat sink is not in contact with said exposed die; and

compressing said gasket with a bottom surface of said die reference heat sink to reduce the height of said gasket until the bottom surface of said heat sink contacts said exposed die.

20. A method according to claim 19, wherein said surface substrate, said gasket and said heat sink form a barrier to suppress EMI emission from said exposed die.

21. A method according to claim 19, wherein said gasket is at least partially made of an electrically conductive material.

22. A method according to claim 19, wherein said gasket is attached to a bottom surface of said heat sink.

23. A method according to claim 19, wherein said gasket absorbs any shocks and vibrations applied to said exposed die.

24. A method according to claim 19, wherein said gasket has bi-linear stiffness, wherein an amount of force for compressing the gasket a unit distance changes to a higher value after the gasket has been compressed to substantially equal the height of the exposed die by the heat sink.