This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Hotspots in microprocessors arise due to non-uniform utilization of the underlying integrated
circuits during chip operation. Conventional liquid cooling using microchannels leads to undercooling of the
hotspot areas and overcooling of the background area of the chip resulting in excessive temperature gradients
across the chip. These in turn adversely affect the chip performance and reliability. This problem becomes
even more acute in multi-core processors where most of the processing power is concentrated in specific
regions of the chip called as cores. We present a 1-dimensional model for quick design of a microchannel
heat sink for targeted, single-phase liquid cooling of hotspots in microprocessors. The method utilizes
simplifying assumptions and analytical equations to arrive at the first estimate of a microchannel heat sink
design that distributes the cooling capacity of the heat sink by adapting the coolant flow and microchannel
size distributions to the microprocessor power map. This distributed cooling in turn minimizes the chip
temperature gradient. The method is formulated to generate a heat sink design for an arbitrary chip power
map and hence can be readily utilized for different chip architectures. It involves optimization of
microchannel widths for various zones of the chip power map under the operational constraints of maximum
pressure drop limit for the heat sink. Additionally, it ensures that the coolant flows uninterrupted through its
entire travel length consisting of microchannels of varying widths. The resulting first design estimate
significantly reduces the computational effort involved in any subsequent CFD analysis required to fine tune
the design for more complex flow situations arising, for example, in manifold microchannel heat sinks
