electronic devices are disclosed that allow for surface - mounting using solder while preventing solder from overflowing between external terminals of the electronic device , or between pads on a circuit board to which the external terminals are soldered . an exemplary electronic device has a base board made of an insulating material and having an outer surface comprising at least one external terminal for surface mounting of the device to the circuit board . a groove is defined at least part way around the external terminal on the outer surface . the groove accommodates overflowed solder and thus prevents unintended spread flow of the solder to locations that otherwise could cause short circuits and the like . the electronic device can include a resin board containing a thermoset resin , wherein the groove is formed by thermal or mechanical processing .