Abstract: A chip mount structure called “subcarrier” and semiconductor device capable of efficiently retaining the temperature of a semiconductor element at a constant level by a Peltier cooler without degrading the signal transmission characteristics of a module even when the atmospheric environment for use in the module changes in outside air temperature are provided. The subcarrier includes an element support unit that is high in thermal conductivity and also an element wiring unit of low thermal conductivity. Increasing the thermal conductivity of element support unit makes it possible to provide superior heat conduction between the semiconductor element and Peltier cooler whereas decreasing the element wiring unit's thermal conductivity enables elimination of radiation and absorption or exchange of heat from the top and side surfaces thereof, which in turn leads to an ability to greatly suppress or minimize the thermal load relative to the Peltier cooler.

Abstract: An ink jet recording sheet comprises a base material made of a transparent plastic film and an ink fixing layer having a pigment fixed by a binder so that an image formed on the ink fixing layer is seen from the side of the base material, wherein the pigment in the ink fixing layer comprises beads of polystyrene or a copolymer thereof. The recording sheet produces a clear image having an excellent color density and no ink bleeding and the like.