all transistor cellular structures are electrically isolated one from each other during the manufacturing process application_number US 30182189 A description power transistor monolithic integrated structures require a high power density per a surface unit in order to be cost effectively manufactured a high power density per a unit area is achievable for example by soldering the transistor chip on a copper mounting plate due to the fact that in a mass production it is not always possible to bond or solder absolutely without the formation of shrink holes and during the final quality control reliably detect the production pieces having fine shrink holes it is unconditionally necessary to provide transistor structures having a 34 selfhealing 34 effect in order to achieve a high reliability of such power transistors it has been already devised to isolate collectors of the individual transistor cell structures one from each other and to create a narrow region in the respective collector conductors leading to a connection spot of the common conductor web if a portion of a transistor cell or of a plurality of transistor cells is heated due to an underlying shrink hole it becomes conductive and passes through almost the entire amount of available current as a consequence the narrow region or regions in the conductor burns up and the transistor cell containing the defective component transistor is separated from the remaining sound part of the power transistor since the melted piece of the defective transistor cell does not take away any base current from the rest of the power transistor the.