Abstract: A printed circuit board according to an embodiment includes: an insulation layer including a recess portion; and a connection pad disposed on the recess portion of the insulation layer and protruded from the recess portion, wherein the connection pad may include a protrusion and a concave portion that is lower than the protrusion, and a surface height of the protrusion of the connection pad may be substantially the same as or less than a surface height of the insulation layer.

Abstract: Disclosed are a cooling device for high temperature fluid, a flight vehicle having the same and a cooling method for high temperature fluid, the cooling device including a heat exchanger configured such that fluid is introduced therein to be heat-exchanged with a refrigerant, and configured to vaporize the refrigerant by the heat exchange such that the fluid is discharged at temperature close to vaporization temperature of the refrigerant, a compressor connected to the heat exchanger and configured to compress the fluid discharged out of the heat exchanger, a turbine connected to the compressor and configured to expand the fluid compressed in the compressor to lower temperature of the compressed fluid, and a phase change heat exchanger connected to the turbine, storing a phase change material, and configured to cause heat exchange between the phase change material and the fluid discharged out of the turbine so as to control temperature of the discharged fluid, whereby a cooling device capable of minimizing in

Abstract: Disclosed is a heat exchanger configured by laminating layers having micro-channels by adapting a micromachining, wherein the micro-channels having uniform length and cross section are constructed within a heat exchanger body in a curved outer shape, thereby minimizing deviation for each channel and improving heat transfer efficiency.