| 摘要 |
PURPOSE:To obtain a printed circuit board to be easily worked on and suited to mass-production by a method wherein metal powder is fixed on a substrate by hardening adhesive, and the substrate is dipped in a molten solder bath to form a conduction pattern is formed by adhering solder with solder adhered on the metal powder. CONSTITUTION:The pattern of an electric circuit is formed on the upper surface of an insulation substrate 10 with epoxy adhesive 11 by means of screen printing. Copper powder 12 is adhered on the adhesive 11 by uniformly spreading the copper powder 12 from above the substrate 10 under the condition where the adhesive 12 is not yet hardened. The copper powder on the part where no adhesive 12 is adhered is removed from the substrate 10 by vibrating the substrate 10. The adhesive 11 is hardened by heating the substrate 10 to fix the copper powder 12 on the substrate 10. The copper powder 12 on the substrate 10 is pickled with dilute sulfuric acid to remove oxide. After the substrate 10 is washed with water and dried, it is dipped in a molten solder bath 13 to adhere solder 13 on the copper powder 12. Then, a conductive pattern 15 is formed on the substrate 10. |
