Printed circuit board design assisting method, printed circuit board design assisting device, and storage medium

A method executed by a computer assisting design of a printed circuit board onto which is to be mounted a grid array package part, said method comprising:

• referring, to positions of a plurality of terminals of said grid array package part, and a part information storer in which are stored attributes indicating whether each of said terminals is a power source terminal or a ground terminal;
• selecting, one at a time, said power source terminals of said grid array package part as a selected terminal to be researched;
• referring to said part information storer and searching for a first new connection path between said selected terminal to be researched, and one of said ground terminals by way of a first decoupling capacitor;
• referring to a connection path storer storing an already-existing connection path between said terminals connected by way of a second decoupling capacitor regarding which placement has already been determined, and determining whether said first new connection path is recorded in said connection path storage;
• storing, using the computer, said first new connection path in said connection path storage when said first new connection path is not recorded in said connection path storage;
• changing a second position of said second decoupling capacitor when said first new connection path is recorded in said connection path storage to secure a placement location for said first new connection path;
• re-searching to find a second new connection path, by way of said second decoupling capacitor, between said terminals connected by said second decoupling capacitor, where said second new connection path does not duplicate said first new connection path;
• and
• deleting said already-existing connection path, which has been the object of said re-searching, from said connection path storage, and storing said second new connection path obtained by said re-searching and said first new connection path, in said connection path storage.

A printed circuit board design assisting device to execute processing of assisting design of a printed circuit board onto which is to be mounted a grid array package part, said device comprising:

• a research object terminal selector referring to positions of a plurality of terminals of said grid array package part, and a part information storage in which are stored attributes indicating whether each of said terminals is a power source terminal or a ground terminal, and selecting, one at a time, said power source terminals of said grid array package part as a selected terminal to be researched;
• a connection path searcher referring to said part information storage and searching for a first new connection path between said selected terminal to be researched and one of said ground terminals by way of a first decoupling capacitor;
• a path duplication determiner referring to said connection path storage storing an already-existing connection path between said terminals connected by way of a second decoupling capacitor regarding which placement has already been determined, and determining whether said first new connection path is recorded in said connection path storage;
• a path re-searcher changing a second position of said second decoupling capacitor when said first new connection path is already recorded in said connection path storage to secure a placement location for said first new connection path, and re-searching to find a second new connection path by way of said second decoupling capacitor, between said terminals connected by said second decoupling capacitor, where said second new connection path does not duplicate said first new connection path;
• and
• a connection path changer storing said first new connection path in said connection path storage when said first new connection path is not recorded in said connection path storage, deleting said already-existing connection path, which has been the object of re-searching, from said connection path storage, and storing said second new connection path obtained by re-searching and said first new connection path, in said connection path storage.