Before printed circuit boards (PCBs) existed, point-to-point construction was used by electric engineers. In point-to-point construction, wires are manually connected from one point to another (hence the name). Although people were able to get by with this type of work, point-to-point construction is costly than a computer-aided design developed by a computer software program and is more prone to human error. Short-circuits and wire failures were also a common problem with this type of set-up.
It was in 1963 when Paul Elsier, an Austrian-born engineer, first invented the PCBs. During this time, Mr. Elsier developed it as a part of a radio. The radio he created was one of the first electronic devices to have a printed circuit board inside it. There were also developments in the processes used in PCBs as early as 1904s when Thomas Edison experimented with plating conductors into linen paper using chemical methods. The United States of America also used them to build proximity fuses back in 1943 for World War II. After the war was finished, commercial use of the PCBs began.
The invention of the printed circuit board was a big leap for the electronics and technology industries as it allowed electronic devices to be reduced to a more comfortable and practical size. PCBs also decreased the human error that can occur during point-to-point construction. Commercially available boards began to increase in size. With smartphones and other portable devices flourishing, it is not surprising that the boards have become smaller to match mobile and miniaturized devices. Fortunately, the size of the PCBs is inversely related to its features and capabilities. Now, most PCBs are equipped with high-performance processors, HD video cards, etc.
Traditionally, PCBs are created as flat, rectangular boards. Nowadays, there are flexible printed circuit boards. High frequency circuit boards are typically produced using rigid boards. Using flexible circuit boards will entail analyzing other additional factors to the materials like the bending properties of the materials and the amount of strain each material and component can take.
Materials used for PCBs have also changed with time. Early PCBs utilized paper saturated with phenolic resin which is commonly known as flame-retardant #2 (FR-2). Flame retardants are materials that are used in the market to prevent the spread of fire or be a safety measure for flammable materials. In the market today, flame-retardant #4 (FR-4) is the most common material used in creation of PCBs. FR-4 refers to printed circuit boards which are composed of fiberglass cloth epoxy laminate sheets. FR-4 became the standard in creating boards because of the rise in powerful processors which in turn needs a more durable PCB.
Old PCBs also made use of lead but in 2006, the European Union (EU) banned the use of lead with the implementation of the Restriction of Hazardous Substances Directive (RoHS). Though it was executed and took effect on July 1, 2006, the European Union adopted RoHS back in February 2003. RoHS is for the reduction of toxic waste and address the high amount of waste that is produced by consumer electronics. Since lead is extensively used for soldering, the ban had a significant effect on the production of PCBs. For this, manufacturers sought new alloys to act as the substitute of lead.
It will not be surprising if other developments in printed circuit boards will come in the next few years or even months. With the fast-pace rate of development in technology, it will not take long for manufacturers to develop and innovate more cost-efficient ways of producing printed circuit boards as well as incorporating high-standard materials in the creation of boards.