Cooling unit

• US 7,337,829 B2
• Filed: 04/07/2003
• Issued: 03/04/2008
• Est. Priority Date: 09/03/1999
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Miyazaki, Ryuuji, Suzuki, Masumi, Hirano, Minoru
• Primary Examiner(s): DUONG, THO V
• Application Number:
  US10/407,464
• Publication Number:
  US 20030188858A1
• Time in Patent Office: 1,793 Days
• Field of Search: 165/80.3, 165/185, 165/104.21, 165/104.29, 361/698, 361/699, 361/700, 361/703, 361/704, 257/714, 257/715
• US Class Current: 165/104.29
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence
• 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 cooling unit has a heat receiving unit that receives heat from a body radiating heat; a radiator disposed at a distance from the heat receiving unit and radiating recovered heat; a liquid coolant transporting heat generated at the heat receiving unit to the radiator; and a hollow tube disposed so that the liquid coolant circulates between the heat receiving unit and the radiator, a circulating flow of the liquid coolant formed by an elevating force of air bubbles generated from the heat received at the heat receiving unit, the radiator having an air pocket forming one part of the circulation path of the liquid coolant together with the hollow tube and capable of collecting the air bubbles.

Claims

1. A cooling unit comprising:

a heat receiving unit that receives heat from a body radiating heat;

a radiator disposed at a distance from the heat receiving unit and radiating recovered heat;

a liquid coolant transporting heat generated at the heat receiving unit to the radiator; and

two distinct hollow tubes disposed so that the liquid coolant circulates between the heat receiving unit and the radiator, each of the hollow tubes forming a separate fluid path between the heat receiving unit and the radiator, the liquid coolant in one tube flowing from the heat receiving unit to the radiator, and the liquid coolant in the other tube flowing from the radiator to the heat receiving unit,

a circulating flow of the liquid coolant formed by an elevating force of air bubbles generated from the heat received at the heat receiving unit, the radiator having an air pocket forming one part of the circulation path of the liquid coolant together with the hollow tubes and capable of collecting the air bubbles,

wherein the heat receiving unit includes a heat sink forming one part of the circulation path of the liquid coolant together with the hollow tubes and the radiator and having a cross-sectional area larger than a cross-sectional area of each hollow tube so as to be capable of collecting a predetermined amount of the liquid coolant so that a portion of the collected liquid coolant turns into air bubbles and flows into one of the hollow tubes and causes liquid coolant to flow with the air bubbles,

wherein said circulating flow of liquid coolant may flow in either of two directions, said flow direction being determined by which direction offers the least internal resistance, and wherein said two hollow tubes connecting the heat sink and the radiator are connected at positions of the same height so that the coolant can flow in either of the two directions.

2. The cooling unit as claimed in claim 1, wherein a flow path is provided in the heat sink so that the liquid coolant flowing from the radiator fully absorbs heat before being returned to the radiator.

3. The cooling unit as claimed in claim 1, wherein a member for improving heat radiation is provided on the radiator.