In general, the master film is also known as the black film, mainly used to copy the work film (yellow film), but not necessarily only a yellow film for work, are also black films do work. It mainly to do high-precision HDI board or to a one-time savings in the production of small quantities of circuit boards and flexibe pcb. Yellow films mainly used in ordinary printed circuit boards and mass production.

Positive film for the use of graphical electroplating, developing is the circuits, leaving the role of anti-corrosion plating, mainly tin and pb plating. Negatives film used for direct etching, leaving the role of circuits. When distinguish the films, the smooth side is black film, in contrast, is yellow film. And generally use scratching pen to scratch the film can be seen smooth side.

Please Note: There are both glossy and matte side of yellow film, and the second is easy to find easy-to-oil surface indentation when using. On film circuits (copper), the transmitting is negative film, opaque positive film.

CMD Circuits is specializing in manufacturing the printed circuit boards, flexible pcb and aluminum pcb, please contact us if any inquiries.