Automatic design method and computer program thereof

An automatic design method for executing, by an arithmetic processing unit, a design process that designs positions where vias are to be disposed on a substrate surface of a semiconductor package by using a virtual plane corresponding to said substrate surface, the method comprising:

• a grouping step of grouping rats and tentatively disposed vias into bonding pad group(s) to be connected, by the bonding pads that are grouped by four sides of the substrate surface of the semiconductor package;
• a boundary line setting step of setting boundary lines to define regions each of which contains any one of said bonding pads and said tentatively disposed vias;
• a checking step of checking whether there exist(s) said tentatively disposed via(s) surrounded by bonding pad group(s) that is/are different from the one to which the via(s) in question belong(s) or not;
• and
• a disposition step of, if it is determined, in said checking step, that said tentatively disposed via(s) surrounded by said different bonding pad group(s) exist(s) singly, moving and redisposing the tentatively disposed via(s) in question on respective position(s) each of which is located on a rat to which the tentatively disposed via in question is connected and on said boundary line that defines a plurality of adjacent regions containing other vias in the bonding pad group to which the tentatively disposed via in question belongs.