Printed Circuit Board Overview


Printed Circuit Boards (PCBs) are also called Printed Wiring Board or Printed Wiring Card. These boards are made of fiberglass covered with plastic and copper tracks. A PCB’s components are connected together by the copper tracks, forming an electronic circuit. So far, this is the most popular and common way of integrating different electronic wires and circuits into a single unit. Overall function heavily lies on the design not only of the printed circuit, but of the whole system.

As such, a designer should give careful attention to the interlinking of traces, grounding, partitioning, decoupling, etc. because all these factors are important for the completion of the whole design and functionality of the circuit board. It should be noted that poor design may result to inefficiency, data corruption, overheating, and other dangerous outcomes.

Where did it come from?

Printed circuit boardThe PCB originated from the concept of wire wrapping. It is a literal wrapping of wires between different terminal points. This is a lengthy method of creating circuits which usually leads to short circuits and failures as time passes (since wire protections get weaker). Later on, integrated circuits and electronics compelled manufacturers to decrease its size and the printed circuit board was born. Nowadays, PCBs are one of the essential components of small and large electronic gadgets alike.

Electronic devices where PCBs are commonly used come in variety of sizes, shapes, and designs. So, the challenge of the electronic industry and manufacturers is to come up with new ways on how to further decrease its size and fit in all the wire systems and multilayer boards with the same or even higher functions into smaller and more compact sizes.

Basic components of PCB

Printed circuit board has multiple layers, copper wires, and silkscreen that are bonded together through lamination and heat, making it a thin and multi-layered circuit.

• Base material (FR4) –

The base material of PCB is also called the substrate and is commonly made of fiberglass or FR4. This is the main component of PCB which keeps its thickness (its rigidity is based on the thickness of its base). PCB base can be made from epoxies and other materials which are cheaper than FR4 but less durable and rigid. PCB’s with these kinds of low-quality base have a differentiating odor. It may also lead to unnecessary failures.

• Copper –

This is a thin foil which is adhesively fused and laminated on the board. The thickness and weight of copper wires vary in each PCB. The number of layers of one PCB ranges from one up to 16 layers.

• Solder mask –

This is put above the copper wire to prevent it from touching other metal parts of the board. This acts as an insulator for the copper wires. The most common color of solder mask is green but it can be any color such as red, violet, etc.

• Silkscreen –

This is another layer placed above the solder mask. Through the use of silkscreen, letters and other symbols can be added to the PCB. These are important indicators of the names and functions of each part of PCB for users to understand the board better. Like the solder mask, the silkscreen is available in other colors (yellow, red, etc.) as well, but it is very rare to see two different colors in one board.

The entire system of printed circuit board may be contained in a small chip, but putting together all its parts, wires and covers is a complex process that requires expert skills and hands. Likewise, there should be a careful layout practice for designing the whole PCB system to optimize its power components and supply.