Positioning device for circuit board tin soldering

The utility model belongs to the technical field of circuit board tin soldering, and particularly relates to a positioning device for circuit board tin soldering, which comprises a workbench provided with a storage rack for placing a circuit board and a chute; the transmission device comprises a transmission screw rod, a first fixing frame and a second fixing frame, the transmission screw rod is arranged in the sliding groove, the two ends of the transmission screw rod are connected to the first fixing frame and the second fixing frame correspondingly, and the transmission screw rod comprises a first threaded section, a middle transition section and a second threaded section which are integrally connected in sequence; the first fixing frame and the second fixing frame are fixedly installed on the two sides of the workbench correspondingly. Each of the two clamping assemblies comprises a fixing seat, a supporting rod, a positioning plate and a limiting plate; the two fixed seats are respectively arranged on th