Conductor pattern check apparatus for locating and repairing short and open circuits

A circuit repair apparatus comprising:

• short-circuit detection means connected selectively to a plurality of conductor patterns formed on a substrate for detecting at least one short-circuited part of said conductor patterns;
• said short-circuit detection means including:
• DC voltage applying means connected selectively to said conductor patterns for applying a predetermined DC voltage to an end of one of said plurality of conductor patterns;
• current measurement means connected selectively to said conductor patterns for measuring a current flowing to another conductor pattern adjacent to said one of the conductor patterns via said end by said DC voltage applied to said end;
• and
• short-circuit position calculation means connected to said current measurement means and said DC voltage applying means for calculating a resistance value from said end to the short-circuited part of said conductor patterns adjacent to each other, based on the current measured by said current measurement means and the voltage applied by said DC voltage applying means, and locating a position of said short-circuited part based on the calculated resistance value and a resistance value of a conductor pattern having no short-circuit;
• laser cutting means connected to said short-circuit detection means for cutting out said short-circuited part detected by said short-circuit detection means by laser;
• disconnection detection means for detecting at least one disconnected part of a plurality of conductor patterns;
• said disconnection detection means including:
• AC voltage applying means for applying a predetermined AC voltage to an end of one of said plurality of conductor patterns,
• voltage measurement means for measuring a voltage at an end of another conductor pattern adjacent to said one of the conductor patterns when the AC voltage is applied to said one of the conductor patterns by said AC voltage applying means, and
• disconnection position calculation means for locating a position of said disconnected part based on a full length of a conductor pattern a voltage measured in a case in which no disconnection is present, and a voltage measured in a case in which a disconnection is present;
• means for placing a solder chip on the disconnected part detected by said disconnection means;
• and
• laser means for applying a laser beam on said solder disconnected part.