BIAS ADJUSTING METHOD

• Main Authors: ONO KAZUTO, TAMAKI TSUTOMU, OKAWA FUTOSHI
• Format: Patent
• Language: English
• Published: 21.08.2008
• Subjects: BASIC ELECTRONIC CIRCUITRY; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; ELECTRICITY; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PULSE TECHNIQUE; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

PROBLEM TO BE SOLVED: To provide a bias adjusting method with which electric characteristics of a circuit unit including a bias circuit comprising an adjustable impedance element and a trimmable resistor, for example, can be easily adjusted into desired characteristics. SOLUTION: A circuit unit 13 is placed on a stage 12 and moved, and a trimming part of a non-illustrated trimmable resistor in the circuit unit is aligned with a laser irradiation head 11a. An external power source 14 is connected to a non-illustrated bias circuit of the circuit unit 13, a supply voltage is varied, characteristics of the circuit unit 13 are measured by a circuit characteristic measuring instrument 16, and a vias voltage Vg0 at a time when desired characteristics can be obtained, is measured by a voltage measuring instrument 15 and stored in a storage device 17. Next, the external power source 14 is detached from the bias circuit, power is supplied from a non-illustrated internal power source to the circuit unit 13 and while a bias voltage of the bias circuit is measured by the voltage measuring instrument 15, the trimming part of the trimmable resistor is irradiated with a laser, and trimming is performed until the bias voltage becomes Vg0. COPYRIGHT: (C)2008,JPO&INPIT