Since they were first invented over a hundred years ago, printed circuit boards (PCBs) have become integral to the electronics industry. The two major divisions of the industry are prototype and production. Prototype circuit boards are designed for specific purposes, and must be assembled according to the specifications. Like other electronics components, PCBs must be disposed of carefully.
Early developments in PCBs
Inventors in Germany, Britain and the U.S. began developing PCBs in the early 20th century, with the basic model of an insulating board on which conducting materials were laminated in a predetermined pattern. Thomas Edison was one of those inventors, and in 1904 he conducted experiments in layering linen paper with conductors using chemical methods.
PCB technology came into large scale use during World War II. By the mid-1950s, with the beginnings of the consumer electronics industry, PCBs came into general use. By 2012, the world market for PCBs amounted to almost $60 billion. This figure represents a 1.7% increase compared to 2011.
Methods of PCB fabrication
There are two major divisions to the industry: prototype PCB and production, or the actual process of PCB fabrication. Prototype pcb fabrication uses two methods: Surface Mount Assembly and Through Hole Construction. Each prototype circuit board is designed for a specific use. The size is designed to fit the space where it will be installed. Computer-aided designs are used to print the circuit designs on the board.
Components can be soldered or layered
Prototype circuit boards are complex and the circuits follow electrical paths that can be separated by spaces as narrow as 0.04 inches or even less. When the prototype PCBs are printed, the location of holes that will be used for leads or contact points are also marked out. In general, PCBs can be single-sided, double-sided, and multi-layered.
Components can be soldered on or layered. There are many different methods for soldering on components. Sometimes very skilled technicians are required to solder on very small parts, like the 0201 packages which measure 0.02 of an inch by 0.01 inch. Newer technologies use curing under pressure and temperature to produce laminates which form a single, integral piece with layers of cloth or paper.
Related technologies are the integrated circuit, also called an IC or microchip, and a hybrid circuit. Like other electronics components, prototype circuit boards pose some problems in terms of disposal. They may contain materials that can be harmful in large concentrations, and they must be disposed of carefully. In some countries like China and Japan, PCBs and other electronic components are recycled and reused.