Browse Prior Art Database

Air Cooling of High-Power Modules with Low Profile Piezoelectric Fans

IP.com Disclosure Number: IPCOM000111309D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Kan, JC: AUTHOR [+2]

Abstract

Disclosed are methods to cool high powered electronic modules using a piezoelectric-type fan 1 as shown in Fig. 1. The piezoelectric fan is a cantilever device in which two metal or plastic blades 2 vibrate back and forth, and is powered electrostatically rather than magnetically. Two-counter oscillating blades are driven at resonance by piezoelectric-bending elements. Because the blades move 180 degrees out of phase with each other, air is forced to move radially outwards. Three system applications are disclosed utilizing this fan. The piezoelectric fan can be side mounted 3 or top mounted 4 (Fig. 2) relative to the module to provide parallel or impinging air flow. Thirdly, a single bladed device 5 (Fig.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 72% of the total text.

Air Cooling of High-Power Modules with Low Profile Piezoelectric Fans

      Disclosed are methods to cool high powered electronic modules
using a piezoelectric-type fan 1 as shown in Fig. 1.  The
piezoelectric fan is a cantilever device in which two metal or
plastic blades 2 vibrate back and forth, and is powered
electrostatically rather than magnetically.  Two-counter oscillating
blades are driven at resonance by piezoelectric-bending elements.
Because the blades move 180 degrees out of phase with each other, air
is forced to move radially outwards.  Three system applications are
disclosed utilizing this fan.  The piezoelectric fan can be side
mounted 3 or top mounted 4 (Fig. 2) relative to the module to provide
parallel or impinging air flow.  Thirdly, a single bladed device 5
(Fig. 3) can be mounted upstream of a heat sink 6 mounted to the top
of a module 7 to induce controlled oscillations of the air entering
the heat sink.  Depending on the frequency of oscillations, heat sink
improvements of up to 30% have been realized.

      By implementing the piezoelectric fan, as described, the
following packaging advantages could be achieved:

1.  Reduce the air flow requirement through each card column.  This
    in turn may reduce the number, flow capacity, and the space of
    the Air Moving Devices (AMDs).  The rotation speed of the system
    AMDs can also be reduced to enhance the reliability.

2.  A reduction in system AMD requirement will also d...