| 摘要 |
<p>PURPOSE:To enable high precision adjustment of resistance value in a high value range in a thick film resistor formed through superposing parts thereof on the conductor layers formed on the insulating base boards by forming the resistor from at least two resistor materials with different sheet resistance values. CONSTITUTION:A low resistance resistor 2 is formed of a low resistance material having a sheet resistance value of 100OMEGA with parts of the resistor 2 being superposed on the conductor layers 1 formed on the insulating base boards. Further, a high resistance resistor 3, contiguous to the low resistance resistor 2, is formed of a high resistance material having a sheet resistance value of 1KOMEGA. The low resistance resistor 2 is cut to form a trimming slot 4 to adjust the resistance value by means of laser trimming so that 99% of the desired resistance value is achieved, and then the high resistance resistor 3 is cut to form a trimming slot 5 to achieve the desired resistance value. If the high resistance resistor 3 is subjected to the trimming after the microcracks 6 originated from the trimming slot 4 in the low resistance resistor 2 become sufficiently stable, high precision trimming can be effected because the influence of microcracks 7 on the resistance value is small.</p> |
