PURPOSE: To obtain an inexpensive device with good heat dissipation properties by a method in which a heat dissipating plate is bonded on a surface of a circuit substrate on which a semiconductor device constituting a hybrid integrated circuit is fixed, and the substrate is dipped in a resin solution to be applied with the resin, which is cured after the resin applied on the surface of the heat dissipating plate is removed.

CONSTITUTION: A semiconductor element 2 constituting a hybrid integrated circuit is fixed on one face of a circuit substrate 1, and is connected to an external terminal 3. A heat dissipating plate 5 is bonded to the other face of the substrate 1. The substrate 1 is dipped in a solution pasted by adding an organic solvent to fine powder consisting of a mixture of heat curable phenol formal-dehyde resin and a filler, so that the whole substrate is coated with this resin 4. The resin 4' on the heat dissipating plate 5 is removed and the residual resin 4 is cured. In such a manner, the heat generated in the element can be dissipated outside through the heat dissipating plate 5 easily and rapidly.