Abstract: The present invention is to provide a real time clock charging circuit mounted on a circuit board, which comprising an booting power input terminal adapted to receive a booting power passed through a first control module to a power storage unit and a second control module; the power storage unit adapted to store the booting power and to output a spare power prohibited from flowing into the first control module and the spare power only flows into the second control module as receiving no input power; a standby power input terminal adapted to receive a standby power to the second control module enabling to output those power to the real time clock and avoiding them to transmit outside.

Abstract: A method of preventing flash between solder pads on a circuit board is proposed. The method involves the step of forming a solder resistant structure on a area between at least two solder pads on the circuit board, such that the solder masks isolates the solder material that flashes between the solder pads, so as to prevent the solder material from flashing adjacent solder pads, thereby eliminating the occurrence of short circuiting.

Abstract: A method for preventing pins of a semiconductor package from short circuit during soldering is provided. The pins are soldered to a circuit board. At least one solder-mask area is formed on the circuit board or the pins, with a solder mask material being disposed on the solder-mask area. When the pins are soldered to the circuit board via a solder material, the solder material flashing to the solder-mask area is prevented to cause electrical connection between the adjacent pins, thereby preventing the pins from short circuit due to solder flash during the soldering process.