Printed circuit boards (PCBs) are important components of electrical appliances and gadgets. Computers, TV sets, cell phones and everything else that run on electrical circuitry have a PCB embedded inside them. If you want to see how a PCB looks like, open up your old desktop computer and look at its motherboard. The motherboard is the largest PCB in the computer and connected to it are smaller motherboards, each one with a specific function that makes your computer system run efficiently.
Before printed circuit boards came into use, you will find messy tangles of wires running in different directions inside an electronic device – for example, radio and television sets manufactured way back in the 1950s until early 1960s. The electrical connections were made with point-to-point wiring that are prone to crack with age, leading to failures at the wire junctions.
Wire wrapping improved the durability of wire connections but added to the cost of production
To meet the increasing demand for electronic products, the need to reduce the size of each device and improve the cost of production resulted to the development of printed circuit boards. The use of PCBs streamlined the design of electronic circuits and significantly reduced the space required to house the electrical components.
The electronic components of a printed circuit board include capacitors, transistors, resistors, diodes and inductors connected by conductive wires where the electricity flows. The mechanical support or main board through which the components are attached is typically fiberglass, while the flow of electricity is supported by conductive traces made from copper.
A PCB loaded with components is called the printed circuit board assembly, which is officially called the circuit card assembly. A variation of the PCB is the printed wiring board wherein the components are not embedded into the board.
The PCB or circuit assembly is a stable combination of complex circuits in a modular design, which utilizes minimal space. It is important in the mass production of complex electronic devices, among these are the appliances and gadgets that we use in our day-to-day activities. The PCB is integral to the electronics industry and is typically used in computer systems for interconnecting components, such as the monitor to the CPU, and the different disk drives to the hard disk drive.
When a circuit board assembly in your computer malfunctions, there is a good chance that you can have it replaced with a unit that can be easily sourced from computer shops and online stores. Fact is, when you open your computer, you will most likely find that the various circuit board assemblies are produced by companies other than the computer manufacturer itself.
Companies that specialize in printed circuit boards, such as pcbnet.com have offshore affiliates that handle the production of these items to meet the demands of the electronic industry. PCB assemblies are produced through a complex manufacturing process, which starts with a design automation tool capturing the desired schematics, developing the design, then proceeding to the creation of the template for mass production.
Automation is employed in the production of PCBs to complete orders of as many as hundreds of thousands in a few days
The automated production starts with the raw circuit board with a non-conductive bottom layer and an upper layer of conductive metal sheet, usually copper. The design is printed into the metal layer with etch-resistant ink, then the raw board is treated with chemicals to etch out the metal, leaving only the metal portions where the designs were printed.
The metal design or trace is the conductive portion of the circuit, which allows current to flow to each of the PCB components. The components are soldered into the board then the production lot is tested before shipping it for distribution.
The consistency, reliability and precision of every PCB unit are assured by the automated systems employed from design to production. PCB assemblies manufactured in the US and in offshore locations comply with the standards set by the IPC (Institute for Printed Circuits) that cover every step of PCB production from design, assembly, testing and acceptance.
The IPC, the Association Connecting Electronics Industries, is responsible for the standardization of the assembly and production requirements of printed circuit boards and other electronic components. The IPC is accredited by the American National Standards Institute (ANSI), which sets global standards for products.