PURPOSE: To prevent deformation of a board component due to compression load fixing such as resistor pressure welding or caulking by making a fixing hole through a fixing component whereas providing a protrusion on a component to be fixed and then fitting the protrusion in the fixing hole and welding them through irradiation of laser beam.

CONSTITUTION: A plurality of fixing holes 13a are made through a fixing board 13 whereas protrusions 11a are embossed on an outer yoke 11. The protrusion 11 is then inserted into the fixing hole 13a and laser beam is projected into a gap Cr in order to weld them at a plurality of points. This assembling method is also employed when an outer yoke 14 and a flange (not shown) are secured and when inner yokes (not shown) are secured to each other. Since this assembling method causes no deformation of the outer yoke or the fixing board and adverse influence of spatter onto the inner pole teeth is eliminated at the time of welding, productivity is improved.