Embodiments of a method for attaching a die to a substrate using a flame or other heat source are disclosed. The NAND structure comprises a first region of a second conductivity type and a second region of the second conductivity type in the substrate, spaced apart from the first region, thereby defining a channel region therebetween. If a pressure drop occurs in the connecting line, a signal change is generated by means of the signal transmitter, whereupon the control unit sends a signal effecting movement of the shut-off valve to its closed position.