The manufacture of Printed Circuit Bboards(PCB) involves both the addition and removal of materials. A non-conductive material is used as the backing of the board. The board is coated with a conductive material such as copper, aluminum or nickel. Circuit boards are generally divided into three types; multi-layered, single-sided or double-sided. The type used will be determined by density and spatial requirements and complexity of the circuits.

Multi-Layer Printed Circuit Board Panel

Multi-layer panels are formed by assembling together inner layer cores. The panels are assembled as a book consisting of layers of copper foil with alternating layers of epoxy sheets known as pre-preg. The book is placed in a lamination press and subjected to high heat and pressure. This melts the pre-preg and produces a bond. The panel is cured in a oven, and trimmed and buffed. Necessary holes are then drilled.

Obtaining Final Thickness

Photo-imaging is used to create the final circuit design. Final thickness is obtained by electroplating copper to the printed circuit. A thin layer of pure tin or lead solder resists are applied to protect the final circuits in the next etching. The plating of resistant tin or lead is removed to expose copper that will not be part of the final circuit. Ammonia-based or sulfuric acid/hydrogen peroxide solutions are used to etch away the unwanted copper.