Abstract: The present invention discloses a gas cooling device and a reflow oven using thereof. The gas cooling device comprises a liquid cooling machine, a plurality condensers and a plurality of outer sleeves. The condensers are disposed in parallel and connected to the liquid cooling machine, in which two ends of all the condensers are separately connected with valves. The outer sleeves are sleeved out of the condensers and communicatively connected in order, in which the outer sleeves disposed at two ends are provided, respectively, with a gas inlet and a gas outlet and each of the condensers is provided with a water outlet. Each of the condensers is formed a circulation with the cooling device. Even though any of the condensers is detached, other condensers are able to continue operating as long as the valves disposed at the two ends of the detached condenser are closed.

Abstract: A printed circuit board (PCB) adapted for mounting different kinds of light sensing modules thereon includes a lighting sensing area and a plurality of pads. The pads are disposed around the lighting sensing area, for configuring one light sensing module thereon. In the present invention, the PCB is suitable for different kinds of light sensing modules without redesign, which lowers the manufacturing cost of the PCB.

Abstract: A printed circuit board (100) includes a plurality of through-holes (140) defined therein, a plurality of first solder pads (110) defined to surround the through-holes respectively, and a second solder pad (190). Each of the first solder pads includes a first soldering zone (112) for accommodating solder used in a soldering process and a second soldering zone (114) for receiving excess solder overflowing from the first soldering zone. The second soldering zone is in communication with and extends outward from the first soldering zone. The second solder pad is located on a tail end of the printed circuit board for receiving excess solder of the tail end during the soldering process.

Abstract: A printed circuit board (PCB) adapted for mounting different kinds of light sensing modules thereon includes a lighting sensing area and a plurality of pads. The pads are disposed around the lighting sensing area, for configuring one light sensing module thereon. In the present invention, the PCB is suitable for different kinds of light sensing modules without redesign, which lowers the manufacturing cost of the PCB.