Processor cooling is undoubtedly the most renowned application for chip coolers. The size of the heat sink and the mounted fan are designed to appropriately suit the power dissipation of the CPU, the dimensions of the processor surface and the available height.
With regard to single board computers or other comparable applications, the processor may under certain circumstances be soldered directly without a base which means that there is no base for attaching a standard cooling system. Other power-hungry components are doubtless installed in close proximity that are generally not of the same height as the processor itself but nevertheless also require cooling. When viewed from the side, this conglomeration of components looks like a small town with buildings of different heights that all require a common roof although not all buildings are required to support the roof construction.
Particularly with compact PCBs, a cooling of diverse hot spots can under certain circumstances result in individual heat sinks becoming inefficient as far as performance and cost-effectiveness are concerned.
It stands to reason that only one heat sink is used and thus only one needs mounting. However, heat sinks with a flat surface cannot usually be used for all electronic components that require cooling as the peripheral components generally have different heights.
SEPA EUROPE has come up with a good idea to solve this problem: a heat sink that is as large as possible and with a milled surface. This ensures that all hot spots are reached and interfering components are omitted. A heat sink profile with adapted base plate and ready-for-connection fan is usually the cleanest and most compact solution for the overall system that is small anyway.