Browse Prior Art Database

Improved Air-Moving Device for Spot-Cooling of Single-Chip Modules

IP.com Disclosure Number: IPCOM000116502D
Original Publication Date: 1995-Sep-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Anderson, TM: AUTHOR [+4]

Abstract

An air-moving device suitable for spot-cooling of high powered single-chip modules that provides for high performance by matching the air-flow velocity profile to the cooling need is disclosed. The concept seeks to provide the ideal fan exhaust velocity profile having a maximum flow speed in the center so that the high impingement velocity and heat transfer coefficient will match the power dissipation distribution right over the die thereby eliminating the bulk of the spreading loss.

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This is the abbreviated version, containing approximately 77% of the total text.

Improved Air-Moving Device for Spot-Cooling of Single-Chip Modules

      An air-moving device suitable for spot-cooling of high powered
single-chip modules that provides for high performance by matching
the air-flow velocity profile to the cooling need is disclosed.  The
concept seeks to provide the ideal fan exhaust velocity profile
having a maximum flow speed in the center so that the high
impingement velocity and heat transfer coefficient will match the
power dissipation distribution right over the die thereby eliminating
the bulk of the spreading loss.

      This is accomplished by inverting the conventional tubeaxial
fan design; the blades are moved to the center, and the motor is
moved to the perimeter.  In one embodiment, the central
hub/bearing/motor region of a conventional fan is grown radially such
that the magnet (101) is attached at the perimeter of, and rotates
with, the centrally-located blade region (102).  The rotating
components are geometrically fixed by a perimeter bearing (103) whose
outer race is held by the stationary hub (104) in order to closely
align the drive coils (105) of the motor.  The control electronics
(106) to commutate the coils can be placed on an annular circuit
board in close proximity to the coils.  The blade shape is such that
the blade pitch decreases with increasing radial location to deliver
a more uniform flow (107).  At the fan exit the actual air velocity
profile will have a small well (or hole) at the very cente...