Thermal interface apparatus, systems, and methods

• US 7,400,040 B2
• Filed: 06/10/2003
• Issued: 07/15/2008
• Est. Priority Date: 06/10/2003
• Status: Active Grant

• Current Assignee: Beijing Xiaomi Mobile Software Co., Ltd. (Xiaomi Corp.)
• Original Assignee: Intel Corporation
• Inventors: Tay, Cheng Siew, Yap, Eng Hooi, Tan, Pek Chew
• Primary Examiner(s): Smith; Zandra V.
• Assistant Examiner(s): Tran; Thanh Y.
• Application Number:
  US10/458,603
• Publication Number:
  US 20040256720A1
• Time in Patent Office: 1,862 Days
• Field of Search: 257/747, 257/748, 257/778, 257/690, 257/734, 257/706, 257/713, 257/635, 257758-759, 257/762, 257773-774, 257/720, 257/741, 257/E23.11, 174254-258, 361/749, 361/750, 361/792, 361/795, 428/29, 428/901, 438107-109
• US Class Current: 257/747
• CPC Class Codes: H01L 23/3735 Laminates or multilayers, e.g. direct bond copper ceramic substrates
• 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 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 2201/068 wherein the coefficient of thermal expansion is important
• CPC Class Codes: H05K 3/4602 characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated
• CPC Class Codes: H05K 3/4641 having integrally laminated metal sheets or special power cores

Abstract

An apparatus and system, as well as fabrication methods therefor, may include a substrate coupled to a first material and a second material. The first and second materials may comprise adjacent metals, and may have different coefficients of thermal expansion sufficient to reduce the amount of substrate warp that can occur due to heating and cooling.

Claims

1. An apparatus, comprising:

an integrated circuit package substrate having a first surface area;

a first material comprising a continuous metal layer of uniform thickness coupled to the integrated circuit package substrate and having a first coefficient of thermal expansion, and further having a second surface area; and

a second material comprising a continuous metal layer of uniform thickness adjacent to the first material coupled to the integrated circuit package substrate and having a second coefficient of thermal expansion different from the first coefficient of thermal expansion to reduce an amount of warp across a surface of the integrated circuit package substrate within a selected temperature range, and further having a third surface area;

wherein the second and third surface areas are substantially similar;

wherein the first material and the second material are embedded in the integrated circuit package substrate;

wherein the first material is located between the second material and a die coupled to the integrated circuit package substrate; and

wherein the first material has a higher coefficient of thermal expansion than a coefficient of thermal expansion of the second material.

2. The apparatus of claim 1, wherein the integrated circuit package substrate is included in a ball grid array.

3. The apparatus of claim 1, wherein the integrated circuit package substrate is included in a printed circuit board.

4. The apparatus of claim 1, wherein the first material and the second material each occupy a substantially similar portion of the integrated circuit package substrate.

5. The apparatus of claim 1, wherein a coefficient of thermal expansion difference ratio between the first material and the second material is less than about 10:

1.

6. A system, comprising:

a wireless transceiver;

an integrated circuit package substrate coupled to the wireless transceiver;

a first material comprising a continuous metal layer coupled to the integrated circuit package substrate and having a first coefficient of thermal expansion; and

a second material comprising a continuous metal layer adjacent to the first material coupled to the integrated circuit package substrate and having a second coefficient of thermal expansion different from the first coefficient of thermal expansion;

wherein the first material and the second material are embedded in the integrated circuit package substrate;

wherein the first material is located between the second material and a die coupled to the integrated circuit package substrate; and

wherein the first material has a higher coefficient of thermal expansion than a coefficient of thermal expansion of the second material.

7. The system of claim 6, further comprising:

a display coupled to a processor and the wireless transceiver.

8. The system of claim 7, wherein the integrated circuit package substrate has a planar surface area, and wherein the first material and the second material each have a surface area greater than about 60% of the planar surface area.

9. The system of claim 7, wherein the wireless transceiver is coupled to an antenna.

10. A method, comprising:

coupling a first material comprising a continuous metal layer having a first coefficient of thermal expansion to an integrated circuit package substrate;

coupling a second material comprising a continuous metal layer adjacent to the first material coupled to the integrated circuit package substrate, the second material having a second coefficient of thermal expansion different from the first coefficient of thermal expansion; and

coupling the first material to the second material;

wherein the first material and the second material are embedded in the integrated circuit package substrate;

wherein the first material is located between the second material and a die coupled to the integrated circuit package substrate; and

wherein the first material has a higher coefficient of thermal expansion than a coefficient of thermal expansion of the second material.

11. The method of claim 10, further comprising:

coupling a die to the integrated circuit package substrate.

12. The method of claim 10, wherein coupling the first material and the second material to the integrated circuit package substrate further comprises:

embedding the first material and the second material in the integrated circuit package substrate.

13. The method of claim 10, further comprising:

determining an amount of warp across a surface of the integrated circuit package substrate over a selected temperature range.

14. The method of claim 10, further comprising:

coupling a wireless transceiver to a circuit coupled to the integrated circuit package substrate.

15. An apparatus, comprising:

an integrated circuit package substrate;

a first material comprising a continuous metal layer coupled to the integrated circuit package substrate and having a first coefficient of thermal expansion; and

a second material comprising a continuous metal layer adjacent to the first material coupled to the integrated circuit package substrate and having a second coefficient of thermal expansion different from the first coefficient of thermal expansion;

wherein the first material and the second material are embedded in the integrated circuit package substrate;

wherein the first material is located between the second material and a die coupled to the integrated circuit package substrate; and

wherein the first material has a higher coefficient of thermal expansion than a coefficient of thermal expansion of the second material.

16. The apparatus of claim 15, wherein the integrated circuit package substrate is included in a ball grid array.

17. The apparatus of claim 15, wherein the integrated circuit package substrate is included in a printed circuit board.

18. The apparatus of claim 15, wherein the first material and the second material each occupy a substantially similar portion of the integrated circuit package substrate.

19. The apparatus of claim 15, wherein a coefficient of thermal expansion difference ratio between the first material and the second material is less than about 10:

1.

20. An apparatus, comprising:

an integrated circuit package substrate;

a first material comprising a continuous metal layer coupled to the integrated circuit package substrate and having a first coefficient of thermal expansion; and

a second material comprising a continuous metal layer adjacent to the first material coupled to the integrated circuit package substrate and having a second coefficient of thermal expansion different from the first coefficient of thermal expansion;

wherein the first material and the second material are embedded in the integrated circuit package substrate;

wherein the first material is located between the second material and a die coupled to the integrated circuit package substrate; and

wherein the second material has a higher coefficient of thermal expansion than a coefficient of thermal expansion of the first material.

21. The apparatus of claim 20, wherein the integrated circuit package substrate is included in a ball grid array.

22. The apparatus of claim 20, wherein the integrated circuit package substrate is included in a printed circuit board.

23. The apparatus of claim 20, wherein the first material and the second material each occupy a substantially similar portion of the integrated circuit package substrate.

24. The apparatus of claim 20, wherein a coefficient of thermal expansion difference ratio between the first material and the second material is less than about 10:

1.