Abstract: In a method of assembling an electronic component onto a substrate, a fiducial is defined by a solder mask positioned upon the substrate. A fiducial-defining window in the mask has a base of the window completely provided with a material of different light-reflecting quality than the mask surface. This provides for the peripheral edge of the window, i.e. the mask, to be the edge of the fiducial. Windows in the mask which expose terminal pads upon the substrate and fixed in position relative to edges of the fiducial and both these windows and the fiducial are determined by the mask. Surface mount components are then located upon the substrate relative to the window positions and not relative to the terminal pad positions. This process reduces the number of incorrect connections of terminals of components to terminal pads.

Abstract: In a method of assembling an electronic component onto a substrate, a fiducial is defined by a solder mask positioned upon the substrate. A fiducial-defining window in the mask has a base of the window completely provided with a material of different light-reflecting quality than the mask surface. This provides for the peripheral edge of the window, i.e. the mask, to be the edge of the fiducial. Windows in the mask which expose terminal pads upon the substrate and fixed in position relative to edges of the fiducial and both these windows and the fiducial are determined by the mask. Surface mount components are then located upon the substrate relative to the window positions and not relative to the terminal pad positions. This process reduces the number of incorrect connections of terminals of components to terminal pads.