A method for forming voids corresponding to pads of SMT components is provided. The method comprises following steps: One or more condition parameters are inputted into a searching unit. The searching unit searches all of the pads with reference to the condition parameters to obtain a pre-selected group of pads. A judgment unit is provided to determine whether each pad of the pre-selected group of pads meets a pre-determined processing requirement to generate a to-be-processed group of pads. An execution unit executes a void formation step with reference to corner coordinates of each of the to-be-processed group of pads, so as to form at least a void at the portion of a contact surface corresponding to a corner of the pad. In an embodiment, four voids which are related to respective corners of each pad of the to-be-processed group are formed at the contact surface accordingly.