Abstract: The present invention provides a circuit board/printed circuit board having pre-reserved conductive heating circuits, which comprises a plurality of metal circuit substrates and a plurality of layers of insulating material. The conductive heating circuits are disposed on the metal circuit substrates. Each of the conductive heating circuits has a plurality of direct heat-generating regions. The insulating material is disposed between the metal circuit substrates. When a current is provided to the conductive heating circuits, heat required for partly bonding and hardening can be generated so that the insulating material and the corresponding positions of the direct heat-generating regions on the metal circuit substrates can be bonded and hardened together. A pre-stacked multi-layer metal circuit board with partly bonding and hardening is thus finished.

Abstract: A limited use circuit in an electronic system that comprises a state machine which controls the operability of the electronic system and determines after boot whether a non-volatile memory device is at its initial data point and then allows the system to operate if it is at its initial data point or cause the electronic system to go down if it is not wherein the state machine is comprised of registers and logic gates or a CPU and a mask circuit and the non-volatile memory device may be selected from the group consisting of PLD, PAL, PLA, EEPROM, FLASH and ROM.