Computer-controlled PCB prodn. line - scans plate cylinder with shiftable lens focusing laser beam

摘要

Automated and simplified production line for p.c.b.s is achieved using offset printing technique without dampening using plates engraved by a computer-controlled laser unit. The unit forming the plates is mechanically connected to the cassette and the printer interacting with the units for mechanical and electrochemical processing. The connection between the units includes a commutating loop fed by the computer while its output is connected to the p.c.b.s printer driving the interrogation signals shaper. The p.c.b.s are made by laser machining with the aid of a scanner exhibiting a scan pulse transducer and plate cylinder revolution sensor. The beam of the laser is modulated and its amplifier is connected to the computer while the interrogation pulse generator is based on pulse repetition frequency multiplier. The plates machined by the laser are coated with oleophobic substance on a heat-insulating sublayer made up of the offset ink. The combination of the laser with computer shortens the process by an order of magnitude by eliminating the photographic processes. The printer (6) is controlled by the computer (I) via connection block (3) and offset plate former (4) and is also linked to the complex (7) for plates processing. The connection block (3) comprises the interrogation pulses generator (15) feeding the shaper (II). The laser machining unit scans the plate cylinder (19) holding the mask plate (20) and is fitted with scan pulse transducer (21) near the laser lens (24).