Heat dissipation for a chip protected by an anti-tamper background

• US 9,066,447 B2
• Filed: 11/03/2011
• Issued: 06/23/2015
• Est. Priority Date: 11/03/2011
• Status: Active Grant

• Current Assignee: CRAM Worldwide LLC
• Original Assignee: CRAM Worldwide LLC
• Inventors: Klum, R. Daren, Fairchild, Matthew D., Hench, Daniel L., Pagan, Keith A., Hagen, Robert Sean
• Primary Examiner(s): SMITH, COURTNEY L
• Application Number:
  US13/288,367
• Publication Number:
  US 20120050998A1
• Time in Patent Office: 1,328 Days
• Field of Search: 361/676, 361/679.54, 361688-722, 361752-760, 361/807, 361/831
• US Class Current: 1/1
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: H05K 5/0208 Interlock mechanisms; Means for avoiding unauthorised use or function, e.g. tamperproof
• CPC Class Codes: H05K 7/20445 the coupling element being an additional piece, e.g. thermal standoff
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

Systems and apparatus disclosed herein provide for heat dissipation from a chip protected by an anti-tamper material. An example electronic device includes a circuit board having electronics mounted thereon, and a security shield covering one or more electronics on the circuit board and configured to sense tampering, the one or more electronics including a chip, the security shield defining an aperture. The device also includes a heat sink extending through the aperture and thermally coupling with the chip, the heat sink extending outside of the security shield.

Claims

1. An electronic device comprising:

a circuit board having one or more electronics mounted thereon;

a housing surrounding the circuit board, the housing comprising at least a first part attached to a second part, wherein the circuit board is mounted to the second part;

a security shield integrated into the first part of the housing and covering the one or more electronics on the circuit board, wherein the one or more electronics are coupled to the security shield, wherein the one or more electronics sense tampering by detecting a change in the security shield, wherein the one or more electronics zeroize data stored in a memory device covered by the security shield in response to such tampering, wherein the one or more electronics include a chip, and the security shield defines an aperture; and

a heat sink extending through the aperture and thermally conductively coupling with the chip, the heat sink extending outside of the security shield.

2. The electronic device of claim 1, wherein the aperture is approximately the same size as an adjacent surface of the chip.

3. The electronic device of claim 1, wherein the aperture is within the range of 0 to 5 millimeters from the adjacent surface of the chip.

4. The electronic device of claim 1, wherein the heat sink includes a plurality of fins extending outside the security shield.

5. The electronic device of claim 1, comprising:

a thermal interface material between the heat sink and the chip.

6. The electronic device of claim 1, wherein the chip comprises a processor.

7. The electronic device of claim 1, wherein the security shield comprises one of a capacitive sensor or a pressure sensor and wherein the one or more electronics covered by the security shield are configured to sense a state of the security shield and zeroize data based on the state.

8. The electronic device of claim 1, wherein the security shield comprises one or more layers of an anti-tamper material that is disposed on the heat sink.

9. A method of manufacturing an electronic device, the method comprising:

forming a first and second part of a housing;

forming a heat sink including a projection;

attaching an anti-tamper material to the heat sink such that the anti-tamper material surrounds the projection and the projection extends through the anti-tamper material, wherein the anti-tamper material senses tampering;

attaching the heat sink and the anti-tamper material to the first part of the housing;

attaching a circuit board to the second part of the housing;

thermally conductively coupling the projection of the heat sink to a chip on the circuit board, wherein data on the circuit board is zeroized in response to tampering; and

connecting the first and second part of the housing to cover the circuit board.

10. The method of claim 9, comprising:

integrating the heat sink into the housing for the circuit board; and

wherein thermally coupling the projection of the heat sink to the chip includes attaching the housing to the circuit board.

11. The method of claim 9, comprising:

coupling the anti-tamper material to tamper responsive electronics on the circuit board such that the tamper responsive electronics zeroize data on the circuit board based on a state of the anti-tamper material.

12. The method of claim 9, comprising:

placing a thermal interface material between the projection of the heat sink and the chip.

13. An electronic device comprising:

a circuit board having a chip and other electronics mounted thereon;

a housing surrounding the circuit board, the housing comprising at least a first part attached to a second part, wherein the circuit board is mounted to the second part;

a heat sink integrated into the first part of the housing and thermally coupled to the chip, the heat sink have an inner surface opposite the chip; and

an anti-tamper material attached to the inner surface of the heat sink, the anti-tamper material disposed to provide tamper protection for the chip, wherein the anti-tamper material senses tampering, wherein data on the circuit board is zeroized in response to tampering, wherein the heat sink extends through the anti-tamper material to thermally couple with the chip.

14. The electronic device of claim 13, wherein the heat sink extends through an aperture in the anti-tamper material that is approximately the same size as an adjacent surface of the chip.

15. The electronic device of claim 14, wherein the aperture is within the range of 0 to 5 millimeters from the adjacent surface of the chip.

16. The electronic device of claim 13, wherein the heat sink includes a plurality of fins extending outside the anti-tamper material.

17. The electronic device of claim 13, comprising:

a thermal interface material between the heat sink and the chip.

18. The electronic device of claim 13, wherein the chip comprises a processor.

19. The electronic device of claim 13, wherein the anti-tamper material comprises one of a capacitive sensor or a pressure sensor and wherein the circuit board includes electronics covered by the anti-tamper material that are configured to sense a state of the anti-tamper material and zeroize data based on the state.

20. The electronic device of claim 13, wherein the anti-tamper material comprises one or more layers of material adhered to the heat sink.