Direct heat pipe contact cooling systems

Direct

— with direct contact, the heat pipes are adjacent directly to the cooled chip and do not have an additional sole; for this, the surface of the tubes on the desired side is ground down to a plane. Due to the absence of intermediate parts, the thermal resistance at the contact points of the heat pipes is minimal, and at the same time, the heatsink design itself is simpler and cheaper than with indirect contact. On the other hand, there are gaps between the heat pipes, sometimes very large — as a result, the surface of the serviced chip is cooled unevenly. This is partly offset by the presence of a substrate (in this case, it fills these gaps) and the use of thermal paste, however, in terms of uniformity of heat removal, direct contact is still inevitably inferior to indirect contact. Therefore, this option is found mainly in inexpensive coolers, although it can also be used in fairly performant solutions.