Abstract: An object with an internal cavity may serve as a cooling structure for a semiconductor package. The object includes a stack of form fitting bodies. The stack has a first form fitting body shaped according to the cavity with a first layer forming a partially form fitting surface, the first layer including a mixture of a first metal and an oxide of the first metal, and a second layer adjacent to the first layer. The second layer includes the first metal but less oxide of the first metal than the first layer. The stack has a second form fitting body shaped according to the cavity with a first layer forming a partially form fitting surface configured to conform to the partially form fitting surface of the first form fitting body.

Abstract: A method for bonding two partially form-fitting surfaces of two metal bodies which contain the same metal is carried out by generating a first layer on the surface of a first one of the two bodies, the first layer containing a mixture of the metal and the oxide of the metal; generating a second layer on the first layer, the second layer containing the metal but less oxide of the metal than does the first layer; placing the partially form-fitting surfaces of the two metal bodies adjacent to each other; heating the bodies placed adjacent to each other to a temperature which lies in a target range below the melting point of the metal and above the eutectic temperature of the eutectic of the metal and the metal oxide; and holding the temperature within the target range over a predetermined or a controllable duration of time.

Abstract: A method for bonding two partially form-fitting surfaces of two metal bodies which contain the same metal is carried out by generating a first layer on the surface of a first one of the two bodies, the first layer containing a mixture of the metal and the oxide of the metal; generating a second layer on the first layer, the second layer containing the metal but less oxide of the metal than does the first layer; placing the partially form-fitting surfaces of the two metal bodies adjacent to each other; heating the bodies placed adjacent to each other to a temperature which lies in a target range below the melting point of the metal and above the eutectic temperature of the eutectic of the metal and the metal oxide; and holding the temperature within the target range over a predetermined or a controllable duration of time.