Package unit, printed board having the same, and electronic apparatus having the printed board

• US 7,221,571 B2
• Filed: 01/17/2006
• Issued: 05/22/2007
• Est. Priority Date: 08/28/2003
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kubo, Hideo
• Primary Examiner(s): Datskovsky; Michael
• Assistant Examiner(s): HOFFBERG, ROBERT JOSEPH
• Application Number:
  US11/332,287
• Publication Number:
  US 20060113105A1
• Time in Patent Office: 490 Days
• Field of Search: 361/707, 361719-720, 361/704, 257712-714
• US Class Current: 361/719
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/27013 for holding or confining the layer connector, e.g. solder flow barrier
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 2224/83051 Forming additional members, e.g. dam structures
• CPC Class Codes: H01L 23/3675 characterised by the shape of the housing
• CPC Class Codes: H01L 23/42 Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
• CPC Class Codes: H01L 23/433 Auxiliary members in containers characterised by their shape, e.g. pistons
• CPC Class Codes: H01L 25/0655 the devices being arranged next to each other
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/19106 in a mirrored arrangement on two different side of a common die mounting substrate
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 2924/3511 : Warping

Abstract

A package unit to be mounted on an external printed board includes a package board mounted with an exoergic circuit element, a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, a joining member that seals between the exoergic circuit element and the heat spreader, and forms a sealing space in cooperation with the exoergic circuit element and the heat spreader, and a liquid metal sealed in the sealing space.

Claims

1. A package unit to be mounted on an external printed board, said package unit comprising:

a package board mounted with an exoergic circuit element;

a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, said heat spreader including a first member and a second member divided from the first member;

a joining member connected to the first member, forming a seal between the exoergic circuit element and said first member, and forming a sealed space in cooperation with the exoergic circuit element and said heat spreader; and

a liquid metal in the sealed space, the sealed space extending between the first member and the second member, a portion of the first member contacting the liquid metal serving as a flat spring.

2. The package unit according to claim 1, wherein said joining member connects the exoergic circuit element to said heat spreader along an outer circumference of the exoergic element.

3. The package unit according to claim 1, wherein said second member has a convex section facing the exoergic circuit element.

4. The package unit according to claim 1, wherein the part of the first member has a thickness between 200 μ

m and 1 mm.

5. The package unit according to claim 1, wherein said joining member is adhesive agent or solid metal.

6. The package unit according to claim 1, further comprising a permission part that permits thermal expansion of the liquid metal.

7. The package unit according to claim 6, wherein the permission part is air sealed in the sealed space.

8. The package unit according to claim 7, wherein the permission part is inert gas that is selected among nitrogen, argon, and helium.

9. The package unit according to claim 6, wherein the permission part is an elastic member provided in the sealed space.

10. The package unit according to claim 1, wherein said heat spreader has a convexoconcave shape on a surface that forms the sealed space.

11. The package unit according to claim 1, wherein said heat spreader is elastic.

12. The package unit according to claim 1, wherein said package board is mounted with plural exoergic circuit elements.

13. The package unit according to claim 1, wherein said package board is made of resin.

14. A printed board comprising a package unit mounted on said printed board, said package unit comprising:

a package board mounted with an exoergic circuit element;

a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, said heat spreader including a first member and a second member divided from the first member;

a joining member connected to the first member, forming a seal between the exoergic circuit element and said first member, and forming a sealed space in cooperation with the exoergic circuit element and said heat spreader; and

a liquid metal in the sealed space, the sealed space extending between the first member and the second member, a portion of the first member contacting the liquid metal serving as a flat spring.

15. An electronic apparatus comprising a printed board mounted with a package unit, said package unit comprising:

a package board mounted with an exoergic circuit element;

a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, said heat spreader including a first member and a second member divided from the first member;

a joining member connected to the first member, forming a seal between the exoergic circuit element and said first member, and forming a sealed space in cooperation with the exoergic circuit element and said heat spreader; and

a liquid metal in the sealed space, the sealed space extending between the first member and the second member, a portion of the first member contacting the liquid metal serving as a flat spring.

16. A package unit to be mounted on an external printed board, said package unit comprising:

a package board mounted with an exoergic circuit element;

a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, said heat spreader including a first member and a second member divided from the first member;

a joining member connected to the first member, forming a seal between the exoergic circuit element and said first member, and forming a sealed space in cooperation with the exoergic circuit element and said heat spreader; and

a liquid metal in the sealed space, the sealed space extending between the first member and the second member, a portion of the first member contacting the liquid metal being flexible.

17. A package unit to be mounted on an external printed board, said package unit comprising:

a package board mounted with an exoergic circuit element;

a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, said heat spreader including a first member and a second member divided from the first member and having a convex section facing the exoergic circuit element, the second member having a notch in the convex section, permitting a thermal expansion of a liquid metal;

a joining member that is connected to the first member, forming a seal between the exoergic circuit element and said first member, and forming a sealed space in cooperation with the exoergic circuit element and said heat spreader; and

the liquid metal sealed in the sealed space.

18. A printed board comprising a package unit mounted on said printed board, said package unit comprising:

a package board mounted with an exoergic circuit element;

a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, said heat spreader including a first member and a second member divided from the first member and having a convex section facing the exoergic circuit element, the second member having a notch in the convex section, permitting thermal expansion of a liquid metal;

a joining member that is connected to the first member, forming a seal between the exoergic circuit element and said first member, and forming a sealed space in cooperation with the exoergic circuit element and said heat spreader; and

the liquid metal sealed in the sealed space.

19. An electronic apparatus comprising a printed board mounted with a package unit, said package unit comprising:

a package board mounted with an exoergic circuit element;

a heat spreader that transmits heat from the exoergic circuit element to a heat sink that radiates the heat, said heat spreader including a first member and a second member divided from the first member and having a convex section facing the exoergic circuit element, the second member having a notch in the convex section, permitting thermal expansion of a liquid metal;

a joining member that is connected to the first member, forming a seal between the exoergic circuit element and said first member, and forming a sealed space in cooperation with the exoergic circuit element and said heat spreader; and

the liquid metal sealed in the sealed space.