PURPOSE: To contrive a cost reduction due to a reduction in a manhour by a method wherein a resistive film formed in a trapezoidal shape is trimmed in a linear form from the upper part of the film extending over the bottom of the film.
CONSTITUTION: An Ag-Pd conductor paste is subjected to screen printing on an alumina ceramic substrate 1 in such a way that its film thickness subsequent to firing is formed in a thickness of 15μm and terminal electrodes 2 are formed by patterning in such a way that one side of the electrodes 2 is slanted at 45° and have been dried. Then, an Ru2O resistive paste is applied in such a way that one part of the resistive paste is applied on the electrodes 2 and after the resistive paste is subjected to screen printing in such a way that its film thickness subsequent to firing is formed in a thickness of 15μm and has been dried, it is calcined for 90 minutes at 800°C, whereby a thick film resistor has been formed. The resistance value of the finished thick film resistor is about 400Ω to the targeted setpoint of 1kΩ±10%. There, a laser beam having an output of 5W and a wavelength of 1.06μm is emitted on the thick film resistor using a YAG laser and a trimming has been performed. As a result, the resistance value can be confined at the setpoint by the emittance only on a linear region 5 and the need to perform an L-type trimming like a conventional method has been eliminated.
KIMURA YUJI
INOUE AKIYOSHI
OKAJIMA NORIMASA
