What Manufacturing Of PCB Entails

By Helene Norris


Printed circuit boards, otherwise known as PCB are found in almost all electronic devices. In manufacturing of PCB, electricians who are amateurs can make their own boards by drawing a design and then giving it to the manufacturer. There are three types; single sided, multi layered and double side boards. They are usually conducted with nickel, copper or aluminum material, and the type used is determined by the complexity and density of the circuits. The process of making them is described below.

The backing is first plated with a conductive material. Holes are then drilled into it in order for conduction to take place in between the layers and also to mount electronic components. The board is then scrubbed to get rid of any small particles of the conductor. Such particles can be later on recycled from the water by using a process such as filtration. Any copper particles left behind can easily mix with other wastes and become pollutant to the environment.

The board is then cleaned. Etching also takes place to allow for proper adhesion in the next stage. Once this has been carried out, there is an addition of another layer of conductor. The process of electrolysis copper plating is applied in order to conduct the holes that had been drilled previously. Both alkaline based and acidic based solutions such as copper sulfate can be used to enhance pH balance.

The final circuit design I achieved by the use of photo imaging. Copper is electroplated to the printed circuit in order to get the final thickness. The final circuits should be well protected in the next etching and it is therefore important to apply a thin layer of lead or tin solder. The copper will be exposed by getting rid of the tin or lead solder, because it will not be a component of the final circuit. The unwanted copper is etched away using either sulfuric acid solution or an ammonia based solution.

Alternative resists can also be obtained by use of other volatile organic compounds or photosensitive ones. These ones can be applied either wet or dry. When exposed to ultraviolet light, the compounds normally harden.

The resists that are in liquid form can be applied using a roller, squeegee, spray or silk screen. This liquid can also be applied to the surface on one or both sides of the surface. Finer circuits can be achieved by using light.

The last stage is the formation of multi layer panels. This is done by assembling together the inner cores of the layer. The assembled panels take the shape of a book that is composed of copper foil that has epoxy sheets alternating with each other.

The book is then placed in a lamination press and high heat and pressure applied to it. The epoxy layers will melt and form a bond. An oven is used to cure the panel. It also undergoes trimming and buffing and then the required holes are finally drilled into it. Summarily, manufacturing of PCB requires a careful and properly calculated procedure in order to achieve the desired results.




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