Bellows heat pipe for thermal control of electronic components

• US 4,951,740 A
• Filed: 06/27/1988
• Issued: 08/28/1990
• Est. Priority Date: 06/27/1988
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation, Texas A&M University System
• Original Assignee: Texas A&M University System
• Inventors: Oktay, Sevgin, Peterson, George P.
• Primary Examiner(s): DAVIS JR, ALBERT
• Application Number:
  US07/211,571
• Time in Patent Office: 792 Days
• Field of Search: 165/32, 165/104.33, 165/80.4, 165/80.2, 165/46, 165/104.26, 361/385
• US Class Current: 165/276
• CPC Class Codes: F28D 15/046 characterised by the material or the construction of the capillary structure
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• 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

Abstract

A bellows type heat pipe which conducts heat away from an electronic device to a heat sink. The heat pipe is a sealed bellows type container which has an evaporator section at one end and a condenser section at an opposite end. The evaporator section contains a saturated radial wick while the condenser section is lined with a radial wick and a circumferential wick. A corrugated slab wick is longitudinally disposed within the heat pipe interconnecting the evaporator and the condenser sections. The evaporator section is placed on the electronic device and the condenser section is enclosed in a housing which is connected to a heat sink. In operation, the electronic device generates heat energy which causes the fluid in the evaporator to vaporize building a vapor pressure in the heat pipe. The heat pipe expands in the direction of the condenser causing the condenser section to make intimate contact with the inside of the housing. The vapors condense at the condenser section and are brought back to the evaporator section via the circumferential wick, the walls of the bellows vessel and the wick slab.

Claims

1. A heat transfer device which comprises a closed cylindrical container including a flexible bellows member with an evaporator section at one end and a condenser section at an opposite end, a first wick lining said evaporator section, a second wick lining said condenser section, and a flexible corrugated slab-type wick longitudinally disposed within the cylindrical container interconnecting said evaporator section and said condenser section.

2. The device of claim 1 wherein and said bellows member is made from copper.

3. A heat transfer device comprising a close hollow cylindrical flexible bellows member adapted to contain a working fluid;

a separate end cap sealingly attached to each opposite end of the bellows member, one end cap defining an evaporator section and the other end cap defining a condenser section;

a first wick lining said evaporator section;

a second wick lining said condenser section; and

a flexible corrugated slab-type wick interconnecting said first and second wicks.

4. A heat transfer device, which comprises:

(a) a flexible cylindrical bellows member having an open end and a closed end with a flat outer surface, said closed end defining an evaporator section which is adapted to contain a body of fluid therein;

(b) a first wick lining said evaporator section;

(c) a rigid cylindrical member having an open end and a closed end with a flat outer surface, the open end of the cylindrical member sealingly attached to the open end of the bellows member to form a sealed container, said rigid cylindrical member defining a condenser section;

(d) a second wick completely lining the inside of the condenser section; and

(e) a flexible corrugated slab-type wick longitudinally disposed within the sealed flexible container, said flexible corrugated slab-type wick interconnecting said first and second wicks.

5. Apparatus for conducting heat away from an electronic device, which comprises:

(a) a heat pipe comprising a flexible bellows member terminating in an evaporator section at one end and a condenser section at an opposite end, a first wick lining said evaporator section;

a second wick lining said condenser section, and a flexible wick longitudinally disposed within said flexible bellows member and interconnecting said first and second wicks;

(b) said evaporator section adapted to be placed on an electronic device capable of generating heat energy when operating and causing said fluid to vaporize thereby building vapor pressure in said heat pipe and expanding it in the direction of the condenser section;

(c) a housing enclosing said condenser section so as to leave an air gap between said condenser and said housing when said electronic device is not generating heat energy; and

(d) a heat sink attached to said housing for conducting heat away from said electronic device.

6. The device as defined in claim 5 wherein said heat sink comprises a cold plate with a through channel for circulating a body of a cold fluid therethrough.

7. Apparatus for conducting heat away from an electronic device, which comprises:

(a) a heat pipe comprising a flexible bellows member defining to an evaporator section at one end and a condenser section at an opposite end, a first wick lining the evaporator section and containing a fluid, a second wick lining the condenser section, and a longitudinally disposed flexible corrugated slab-type wick within said flexible bellows member and interconnected to said first and second wicks;

(b) said evaporator section adapted to be placed on an electronic device characterized by generating heat when operating sufficient to cause a fluid within the evaporator section to vaporize; and

(c) said condenser section of said heat pipe attached to a heat sink means.

8. The device as defined in claim 7 wherein said heat sink comprises a cold plate with a through channel for circulating a cold fluid therethrough.

9. Apparatus of claim 7 wherein said evaporator section is permanently cemented on said electronic device.

10. Apparatus of claim 7 wherein said evaporator section is soldered on said electronic device.

11. Apparatus of claim 7 wherein said condenser section has an inner circumferential wall and a flat inside and a flat outside surface.

12. Apparatus of claim 11 wherein said second wick comprises a radial wick which lines the flat inside surface of the condenser section and a circumferential wick which lines the inner circumferential walls of the condenser section.

13. Apparatus for transferring heat from an electronic device to a heat sink, said electronic device generating heat energy when operating, said apparatus comprising:

(a) a cylindrical heat pipe comprising;

(i) an evaporator section and a condenser section sealingly attached to opposite ends of a hollow flexible bellows member to form a sealed flexible container;

(ii) a first wick saturated with a fluid lining the evaporator section;

(iii) a second wick completely lining the condenser section; and

(iv) a flexible corrugated slab wick longitudinally disposed within the sealed flexible container and attached to said first and second wicks;

(b) said evaporator section of the heat pipe adapted to be placed on said electronic device via a layer of a thermal epoxy, the heat energy from the electronic device when operating vaporizing the fluid in the evaporator section and causing vapor pressure to be built in the heat pipe so as to expand the heat pipe in the direction of the condenser section;

(c) a housing enclosing said condenser section while providing a gap of predetermined width between the housing and the condenser section when the electronic device is not generating said heat energy; and

(d) a cold plate attached to said housing, said cold plate having channels there through for circulating a cold fluid, said cold plate acting as the heat sink.