METHOD OF FORMING EXPOSED CIRCUIT PATTERNS OF PRINTED CIRCUIT BOARD(PCB)

摘要

PURPOSE: A method of forming exposed circuit patterns of a printed circuit board(PCB) is provided to simplify the forming operation and increase the precision simultaneously and enable an integrated or small PCB. CONSTITUTION: In a method of forming exposed circuit patterns, circuit patterns are formed on a board(21). Solder resist(25) is applied on a board(21) formed with circuit patterns(22). The solder resist(25) is hardened as insulation. Certain parts of the solder resist(25) are eliminated selectively by laser(L) projected until the circuit patterns are exposed, accomplishing a solder land(30). By using a laser(L), errors can be reduced noticeably and thus manufacturing steps can be streamlined. And the PCB can be reduced in size as the pitch(P) between the solder land (30) and the circuit pattern(22) is reduced.