Browse Prior Art Database

Conduction-Coupled Low Temperature Central Electronics Complex (CEC) Cooling

IP.com Disclosure Number: IPCOM000013808D
Original Publication Date: 2000-May-01
Included in the Prior Art Database: 2003-Jun-18
Document File: 3 page(s) / 48K

Publishing Venue

IBM

Abstract

Now that the limitations of bulk CMOS scaling are imminent, other means to enhance circuit performance may be considered. One of those means is to operate the circuits at low temperatures, possibly within the cryogenic temperature range (150K and below). Condensation becomes an issue at low temperatures because water is detrimental to the operation and reliability of electronic components. There are two general methods by which to mitigate condensation: 1) maintain the electronics above the environmental dew point temperature; or 2) maintain the dew point temperature below that of the electronics. As the operating temperature is reduced, the first method of mitigation becomes increasingly undesirable. Guard heating is needed to maintain surface temperatures above dew point; and the lower the operating temperature, the more guard heating is required thereby increasing the total heat load on the refrigeration system providing the low temperature cooling. Dew point control becomes a more attractive means of condensation control, but then the electronics must be enclosed in a compartment that minimizes the ingress of moisture into the environment being controlled. Incorporating this into a computer application would require the compartment to enclose the Central Electronics Complex (CEC) which would result in the loss of air flow currently used to cool the memory/power books. Disclosed herein is a method to remove heat generated within the CEC without air flow so that the CEC can be compartmentalized for dew point temperature control. In short, the refrigeration system used to cool the central processor would serve as the heat sink for the CEC with the memory/power books being conduction-coupled to the evaporator cooling the CPU. Figure 1 illustrates the concept of thermally coupling the memory books to the evaporator, by means of thermal conduction, so that they may be cooled without system air flow. It should be

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  Conduction-Coupled Low Temperature Central Electronics Complex (CEC) Cooling

Now that the limitations of bulk CMOS scaling are imminent, other means to enhance circuit performance may be considered. One of those means is to operate the circuits at low temperatures, possibly within the cryogenic temperature range (150K and below). Condensation becomes an issue at low temperatures because water is detrimental to the operation and reliability of electronic components. There are two general methods by which to mitigate condensation: 1) maintain the electronics above the environmental dew point temperature; or 2) maintain the dew point temperature below that of the electronics. As the operating temperature is reduced, the first method of mitigation becomes increasingly undesirable. Guard heating is needed to maintain surface temperatures above dew point; and the lower the operating temperature, the more guard heating is required thereby increasing the total heat load on the refrigeration system providing the low temperature cooling.

Dew point control becomes a more attractive means of condensation control, but then the electronics must be enclosed in a compartment that minimizes the ingress of moisture into the environment being controlled. Incorporating this into a computer application would require the compartment to enclose the Central Electronics Complex (CEC) which would result in the loss of air flow currently used to cool the memory/power books. Disclosed herein is a method to remove heat generated within the CEC without air flow so that the CEC can be compartmentalized for dew point temperature control. In short, the refrigeration system used to cool the central processor would serve as the heat sink for the CEC with the memory/power books being conduction-coupled to the evaporator cooling
the CPU.

Figure 1 illustrates the concept of thermally coupling the memory books to the evaporator, by means of thermal conduction, so that they may be cooled without system air flow. It should be

1

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understood that this method may also be applied to cooling other cards/books connected to the CEC board. Currently, an S390 processor module is bolted to the CEC board front...