A device for etching the backside of a wafer is disclosed. The self-organizing networks can include a computing cloud component coupled to the heterogeneous mesh network. The thin film transistor is provided at an intersection of a gate line and a data line on the lower substrate, and the gate line and the data line cross at right angles. The first part has the first outer wall, and at least the first part has a first set of indentations on a first inner wall opposite to the first outer wall, and wherein those indentations are closed off by the second part on the wall opposite of the first outer wall when the cooling body is assembled, thus creating the cooling channel.