A Brief Introduction To Printed Circuit Board Technology

By Adrian Cruce

A Printed Circuit Board (PCB) is an integrated circuit device that is printed on the surface of a substrate and uses mechanical action to support and connect electrical or mechanical components with conductive pads, traces and other attributes etched into one or more layers of various non-metallic, moisture-absorbent or perfusable material. This can be printed on a wide variety of substrates including glass, silicon, wood, metal and also plastic. Many different devices can be built and attached to a Printed Circuit Board including cell phones, personal digital assistants (PDAs), laptop computers, game consoles, car navigation systems, television sets, medical equipment and any type of industrial or commercial equipment. The use of Printed Circuit Boards in these applications has increased dramatically over the last 20 years and continues to grow at a rapid pace.

There are two types of Printed Circuit Boards (PCBs): active and passive. An active pcb is a closed circuit system that requires power for its operation and must be connected to a power source and is generally an IC like a microprocessor, digital LED, resistive or capacitive touchscreen, etc. The active pcb is very easy to work with since it has direct connection to a power source and can be programmed in various ways such as over or under current, switching modes and some even have programmable jumpers and flashing lights. Passive pcb’s are much less popular and are used in applications where it is not practical or cost effective to implement a programmable device. Examples of passive pcb’s that are used widely in the market include remote control units, toys, telephones, PDA’s, personal digital assistants (PDAs), LCD monitors, wireless communication boards, portable personal digital assistants (PDA’s), global positioning systems, etc.

A printed circuit board comes in various different forms, sizes, thicknesses and cost factors. The cost factor per job also varies. The most expensive type of job comes in form of an etched circuit board which has an etched pattern made of etched glass on the top surface and is the most difficult type of printed circuit board to assemble. It also costs the most. Next, the most affordable web is the one with a printed circuit on the front and is the easiest to assemble and install.

An open-frame Printed circuit board has no electrical connections and its main function is to carry the signals from one input component to another without using mechanical contacts. It is the simplest form of a printed circuit board but the drawback is its limited space because it has to be electronically connectable components. The space constraint of this type of board makes it unsuitable for some industrial applications such as printing. It also has less robust components compared to the other two types. However, as technology advances, new types of open-frame PCBs are being developed which has more features and greater reliability and performance compared to the older ones.

Basically, there are five basic web design structures available in the market today from printed circuit board companies. The first one is the barebone board which has no circuit layer and the only components are the power and input connectors. This is the least expensive option for new product development. The second option is the semi-conductor system which has several layers and it is like a stack of thin electrophoresis resistors or even metal traces etched on the board’s surface. The most popular and versatile option is the multilayer system which has five to eight layers and it is the most flexible in nature. The last choice is the HDL or High-level HDL which has higher specification than the previous three types.

With a fully assembled and configured Pcb, electronics manufacturers can create a wide range of designs including full range of signal traces, attachment to devices and mounting systems. This will help reduce time and cost for electronics designing. Furthermore, the complexity of the project will definitely increase once electronics engineers finish the project with a layout and wiring diagram. The layout and wiring diagrams allow for easier attachment of cables and connections between boards. A good layout will also facilitate easy routing of wiring traces.

A new type of Printed circuit board called the surface mounted assembly has a very simple design and does not have wiring connections. This type of board does not have hole drilling facilities, so the programmer will have to manually drill the appropriate holes. The holes will be automatically drilled using Methylene spreader bars. There are also surface mounted assemblies that have PC board mounting options wherein the programmer will be provided with M screws to mount the board in a standard manner. This option is faster because it does not require manual drilling and provides easy connection points.

All three types of PCB technology offer different solutions for electrically wired and unwired electronic circuits. However, the latest innovation, the flex circuit board offers an option for connecting two electrically connected circuits. This flexibility is made possible with the use of PC board mounting accessories such as cable guides, flex clips and push fit connectors. It is designed for flexible installation and eliminates the need for expensive electrical drill holes.