| 摘要 |
PURPOSE:To contrive high speed in a trimming by a method wherein positions on a trimmed resistor are always monitored, but the judgement of circuit element values is inhibited in some sections when trimming a trimmed resistor by continuously scanning a laser beam. CONSTITUTION:When trimming a trimmed resistor 2 to a target value by continuously scanning a laser beam, sections 38-39, 40-41, 42-43, 44-45, 46-47 which inhibit the measurement-comparison of the target value are settled in a coarse adjustment ladder part 3. When the trimmed resistor value reaches the coarse adjustment target value on the release of the measurement-comparison, the coarse adjustment is completed and turns to a fine adjustment 5. Otherwise, the same operation is successively repeated through ladder chips 3b-3e. Thus, a laser trimming is performed with high speed and high reliability. |
