Wednesday 22 May 2013

Important Facts Relevant To The Manufacturing Of PCB Boards

By Carissa Glenn


A printed circuit board is an essential part of electrically and mechanically driven devices. It is used in connecting and supporting electronic components with an electrically charged tract from the copper sheet laminated on non conductive substrate. PCB is heavily populated with different electrical elements collectively known as printed circuit assembly. The manufacturing of PCB boards entails a systematic approach where only the ones who have the ropes are allowed to work.

A printed circuit board design is not done based only on the creativity and resourcefulness of a fabricator. Design, assembly as well as quality control needs are identified by the Association Connecting Electronics Industries or IPC organization, a trade association that wishes to establish standardized assembly and production of any electronic equipment. This is why PCBs need to be initially designed before they go out to the market.

First introduced in the early 20th century, the modern printed circuit boards were created by a German inventor named Albert Hanson which was also developed by an American businessman and inventor, Thomas Edison. In 1904, Edison experimented chemical methods in plating conductors using linen paper. And it was in 1913 that a certain electronics company patented a print-and-etch technique.

Later on, an Austrian engineer named Paul Eister created a printed circuit for a radio set. The technology began to spread in the U. S. In 1943 as an essential component of a proximity fuse. Proximity fuses were explosive devices used during the second World War. These automatically blew up upon drawing nearer to a target.

Just before the prototype of this technology was released, manufacturers used the point-to-point strategy of construction. It is a non automated approach used in the construction of electronic circuits. And between 1936 and 1947, another distinguished company offered new developments of the device through spraying this on plastic board.

But before all these enhancements, electronic components had wire leads which passed through holes and were soldered into the trace of a PCB. This construction method is known as through hole, an electronic approach which involves a certain mounting scheme as well as the use of lead on every component inserted in the board's holes. By and large, this is manually performed.

In the 1980s, the surface-mount device was introduced by which electronic circuits had to be mounted on the board's surface directly. This technology prompted production of smaller devices and eventually replaced through-hole construction. Both technologies, however, could be used in the same board.

Manufacturers today largely use laminates, copper-clad laminates, resin Pre-preg and copper foil. Laminates are fabricated through using a thermosetting plastic resin in creating integral pieces with uniform thickness. Common length runs from four to eight feet. Standard resin percentage, cloth weaves and thickness are required in achieving the desired dielectric characteristics. The cloth used will determine the ratio of the resin in the laminate being produced.

Manufacturing of PCB boards also passes through subtractive processes. These involve silk screenings printing, photoengraving and PCB milling. Circuit properties also require chemical etching, a subtractive manufacturing process that is now increasingly important in the production of the board.




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