| 摘要 |
<p>PROBLEM TO BE SOLVED: To shorten time necessary for laser trimming by notching a part in a trimming trench which part is positioned outside a side surface edge of a resistance film at a trimming speed higher than that of notching the resistance film in the trimming trench. SOLUTION: A laser ray is cast on a resistance film 2 on an upper surface of each insulating substrate 1 in a base substance substrate A from an upper part of a cover coat 4, and a trimming trench 5 is notched so as to stretch in an L-shape from a start tip 5a positioned outside a side surface edge 2a of the resistance film 2 to the resistance film 2. When this notching is performed, a part from the start tip 5a to an almost side surface edge 2a of the resistance film 2 in the trimming trench 5, i.e., a part outside the side surface edge 2a of the resistance film 2 which part has a length L1 is notched at a trimming speed higher than that of notching a part of the resistance film 2 in the trimming trench 5. The above laser trimming is performed to all the insulating substrates 1 while the base substance substrate A is moved in a longitudinal and a lateral directions.</p> |
