History

• Connecting parts of electrical devices by wire laid out on wood has existed since the second half of the 19th century. During the 20th century, this developed into printing conductive circuits with a stencil on a surface.
  
  

Time Frame

• According to the U.S. Patent database, the first patent (2756485) for a printed circuit board was issued July 31, 1956 to M. Abramson, although an Austrian made one in England in 1936.
  
  

Features

• Printed circuit boards are composed of fiberglass bonded to copper foil. The board is etched according to specifications for the particular product so that unnecessary copper is removed, leaving just the needed circuits.
  
  

Benefits

• Using printed circuit boards reduces manufacturing costs, allows for standardization, provides the most compact way of wiring circuits in devices and allows more components to be placed in small spaces.
  
  

Potential

• Miniaturization continues decreasing the size of components such as transistors and packing more patterns on a circuit board. There is an upper limit to how close printed wiring can be, which eventually will require another approach.