Abstract: An improved fastener includes a fastener body and a blocker. The fastener body has an end functioning as a connecting head, and center of the fastener body forms an axial threaded bore. An end of the axial threaded bore corresponding to the connecting head is formed into a recess surrounded by the connecting head. The blocker is removably fitted in the recess of the fastener body. When the connecting head of the fastener body is extended through a fixing hole on a printed circuit board with the blocker fitted in the recess, solder paste applied over the fixing hole is prevented from entering into the axial threaded bore of the fastener body to interfere with a screw being threaded into the fastener body.

Abstract: A packaging method for assembling a screw to a printed circuit board (PCB) includes the steps of: providing a screw having a head, a threaded shank, and a ferrule enclosing the threaded shank; mounting a stop ring on the threaded shank to maintain a predetermined height from top of the head to bottom of the ferrule; using a tool to fetch the screw and align the threaded shank with one through hole provided on the PCB; releasing the screw from the tool for a flange of the ferrule to extend into the through hole on the PCB; heating to melt a solder layer atop of the PCB, so that the ferrule is fixedly held to the PCB when the molten solder layer is cooled and hardened again; and removing the stop ring so that the threaded shank is retracted into the ferrule.