In a method for producing a circuit board for a semiconductor package, portions of the resist film formed on the respective surface of the core substrate are removed during the exposure/development process, which portions correspond to the circuit pattern and to the cavity opening but having a diameter...http://www.google.ca/patents/US5858816?utm_source=gb-gplus-sharePatent US5858816 - Method for producing circuit board, for semiconductor package, having cavity for accommodating semiconductor element
