Browse Prior Art Database

Variable-Speed Cooling Assembly for a Processor Chip

IP.com Disclosure Number: IPCOM000116329D
Original Publication Date: 1995-Aug-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Kamath, V: AUTHOR [+2]

Abstract

Disclosed is a cooling assembly including a fan directing air through a heat sink mounted to a case of a processor chip within a desktop computing system. The speed of the fan is controlled as a function of the temperature measured by a thermistor mounted directly on the heat sink. The system is turned off when the temperature measured by the thermistor exceeds a pre-set limit or when a fan malfunction is detected by current sensing means in the fan circuit.

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This is the abbreviated version, containing approximately 52% of the total text.

Variable-Speed Cooling Assembly for a Processor Chip

      Disclosed is a cooling assembly including a fan directing air
through a heat sink mounted to a case of a processor chip within a
desktop computing system.  The speed of the fan is controlled as a
function of the temperature measured by a thermistor mounted directly
on the heat sink.  The system is turned off when the temperature
measured by the thermistor exceeds a pre-set limit or when a fan
malfunction is detected by current sensing means in the fan circuit.

      The Figure is a partly cross-sectional elevation of a processor
chip 1 and an attached cooling assembly 2.  Within processor chip 1,
electrical connections from a circuit chip 3 are made through a
ceramic substrate 4 to external contacts 5.  Within cooling assembly
2, a Direct Current (DC) axial-flow fan 6 is mounted among
upward-extending pins 7 of a heat sink 8, to which a thermistor 9 is
attached.  Circuits for controlling the fan speed as a function of
the temperature measured by the thermister, and for determining if
the system should be turned off, are incorporated in the fan 6 or in
a system board 10 to which the processor chip 1 is attached.  With
fans having a diameter of 92 millimeters or greater, either of these
methods can be used; with smaller fans, these circuits are preferably
on system board 10.

      Because heat sink 8 is directly mounted to the ceramic
substrate 4 forming the case of processor chip 1, the temperature of
bas...