The dimensions of the mounting pads are determined by taking into consideration such factors as solderability and insulation. This is done in order to accommodate the mounting accuracy of an automatic mounter. The dimensions of the mounting pads in the catalog may be used.
 

A relay weighs several grams, which is much heavier than chip components such as capacitors and resistors. Therefore, the self-alignment effect of molten solder surface tension with respect to the mounting pad cannot be expected. It is therefore recommended that the relay be temporarily secured to the printed circuit board with epoxy-type glue to prevent the relay from being dislocated due to vibration while it is transported before soldering. The projections on the printed circuit board to which the relay is to be glued are called glue pad projections. Secure the relay on the board by applying adhesive to the glue pad projections.

The SMT relay is highly resistant to heat. The relay should be soldered under the correct temperature conditions so that the full performance of the relay can be realized. The IRS (infrared ray reflow soldering) and VPS (vapor phase soldering: reflow by using latent heat of organic solvent) methods are recommended.

Air reflow soldering may also be used. Whichever soldering method is used, be sure to confirm the temperature conditions for soldering and the influence of soldering on the relay in advance before setting work standards.