PURPOSE: To obtain conductive copper paste having high bonding strength to a board and capable of forming a thick copper film conductor by incorporating the same components as those of glass and incorporating glass frit having specific average particle size and conductive copper powder therein.

CONSTITUTION: Glass frit containing aluminum calcium borosilicate having 2μm or less of average particle size and conductive copper powder having 1-2μm of average particle size are vigorously agitated while applying an ultrasonic vibration thereto to be mixed. The mixture is dispersed in an organic vehicle, and kneaded to form conductive copper paste. The paste is screen printed in a predetermined shape on a low temperature based board formed of glass containing the same components as those of the glass frit contained in the paste and alumina, preliminarily dried, and baked at 750°C or lower in a nitrogen atmosphere to obtain a thick conductor copper film.