In the electronic boards like, PCBs or, printed circuit boards are used to mechanically support electronic components which have their connection leads soldered on top of copper pad in plane mount applications. These electronic components will be drilled holes in the electronic board and copper pads for soldering the component leads in thru-hole applications. A electronic board design may have all thru-hole components on the top or component side, a mix of thru-hole and surface mount on the top side only, a mix of thru-hole and surface mount components on the top side and surface mount components on the bottom or circuit side, or surface mount components on the top and bottom sides of the board.
The PCBA design boards are also used to connect electrically the necessary leads for each component using conductive copper traces. The component fillings and connection traces are fixed from copper sheets coated onto a non-conductive substrate. Printed circuit boards or PCBA are designed as single sided with copper fillings and traces on one side of the board only, double sided with copper pads and traces on the top and bottom sides of the board, or multilayer designs with copper pads and traces on top and bottom of board with a variable number of interior copper layers with traces and connections.
A non-conductive (non-coherent) base is used to fix the component traces with the copper sheets. A PCBA can be designed in multiple ways. They could be one sided with copper fillings on one side of the base. Conductive copper traces can be connected via electrical wires using PCB’s. They could be also havings copper tracings on upper and lower layers. On third option can be of multiple layers with copper traces on all the inner sides too.
A core dielectric material is found in single or double layered boards. They consist of FR-4 epoxy fiberglass, with copper plating on one or both sides. When the board is in the process of getting manufactured the copper plate is mounted to form actual copper pads. In a multilayer board there are layers of dielectric stuffs separated by adhesives and these layers in turn separate the copper plates. Now under the influence of heat and pressure the layers are aligned together. Using modern techniques we can produce multi board layers with more than 48 layers.
In a simple design using 4 layer method internal layers provides access to power and ground connections like 5 volts plane layer and ground layer acts as two internal layers. All the connections are on top and bottom layers of board. These designs which are very complex have large number of layers to make various connections for different level of voltage and ground connections and to connect the leads on ball grid array devices.
The multi layered board has two ways of formation.
a) Pre-preg material which is thin flakes sort of layers of fiber glass coated with an adhesive and is in sheet form generally 0.02 inches thick.
b) Core material is exactly like thin double sided board and it has to be dielectric board like an epoxy fiber glass with layers of copper on both sides. They are basically 0.3 inches thick di electric materials with an ounce of copper on each side.
There are usually two types of material used to construct a multilayer board. Pre-preg material is thin layers of fiberglass pre-impregnated with an adhesive, and is in sheet form, usually about .002 inches thick. Core material is similar to a very thin double sided board in that it has a dielectric material, such as epoxy fiberglass, with a copper layer deposited on each side, usually .030 thickness dielectric material with 1 ounce copper layer on each side. In a multilayer board design, there are two methods used to build up the desired number of layers. The core stack-up method, which is an older technology, uses a center layer of pre-preg material with a layer of core material above and another layer of core material below. This combination of one pre-preg layer and two core layers would make a 4 layer board.
