Printed circuit boards play a very important role in modern society, and are used in a huge variety of products and components. The circuit board industry developed in the 1960s, where photo chemical milling or etching was used to fabricate the many boards that came into use. Photo chemical milling is also known as photo chemical machining , and has since been used in the fabrication of a number of other parts and components. Printed circuit boards are typically made using the process of etching, with a copper bonding first placed over a substrate. Once an entire copper layer has been added, the unwanted copper is taken away, leaving only the desired copper traces that are used to create connections between different components and parts of the board. Read more