Abstract: A housing for accommodation of a plurality of electric circuitry packages, a method for assembling the housing, a cooling arrangement, and an electrical connection arrangement are disclosed. The housing can accommodate a plurality of packages, supply the packages with power, connect them electrically, support them and cool them. By means of the resilient support, the housing can withstand and protect the packages from shocks and vibrations. By means of the resilient connection, the housing can handle package size differences, e.g. due to thermal expansion caused by temperature changes. The cooling arrangement for cooling the electric circuitry packages includes several cooling units sandwiched with the packages into a stack. A cooling fluid cools the packages by flowing through each cooling unit. The units have flexible package facing walls, which form themselves to the package surfaces due to the cooling fluid pressure.