METHOD OF LASER-TRIMMING FOR RESISTOR-EMBEDDED PRINTED CIRCUIT BOARD

• Main Authors: YOON, SANG KOWN, LEE, HAN SUNG
• Format: Patent
• Language: English
• Published: 16.05.2008
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS

A method of laser-trimming for a resistor-embedded printed circuit board is provided to implement management of resistance tolerance of less than ±1% regardless of resistor material by offsetting a resistance measurement error due to heat generated in a laser process of a resistor. A method of laser-trimming for a resistor-embedded printed circuit board includes the step of: finely controlling a resistance by forming a rectangular resistor(20) by printing the resistor with predetermined length and width with carbon paste on a screen between a pair of copper clad electrode pads(10) and then locally removing the carbon paste by irradiating laser beams on a surface of the resistor, wherein a trim process is performed by irradiating the laser beam with measuring the resistance in real time through probes(40) in contact with the both copper clad electrodes and heat of a region of the resistor with a trim(100) is discharged to cool the resistor by locally injecting air on the surface of the resistor on which the trim process is performed through an air nozzle(80).