Most Common Components Used in PCBA

Most Common Components Used in PCBA

An Electronics Assembly Bill of Material (BoM) has some basic components those are summarized in a few categories. These components take the bulk of sourcing efforts. In this article, we try to articulate these common component types.

The following components are some of the most commonly used parts in electronics assembly.

  • Resistors
  • Capacitors
  • Diodes
  • Integrated Circuits
  • Transistors


A resistor is one of the most common electronic components you will come across in the assembly project. In electronics assembly, resistors are categorized based on their power ratings and resistance values. Resistance values are measured in unit ohms.


Capacitor is another type of component that is commonly found in electronics assembly project. It can store an electrical charge for a short amount of time. There is a large variety of capacitors but the most common types are electrolytic and ceramic disk. The electrical charge retention capacity (capacitance) of capacitors is measured in farad (F) and the charge itself is measured in volt (V).


The role of a diode is to make sure electrical current flows in a single direction. A diode has two terminals, cathode, and anode. To make the current flow, the anode is charged with positive voltage and cathode is charged with negative voltage; when this process is reversed, the flow of current stops.

Integrated Circuits:

An Integrated Circuit (IC) is a semiconductor silicon wafer generally consists of thousands or millions of tiny components such as resistors, capacitors, and transistors. It is also called chip or microchip fabricated in a way that it can process a simple function or multiple complex functions.


The transistor is a semiconductor component that is used to amplify switch electrical power or electronic signals. It is easy to identify because of their three terminals.

Apart from these components listed above, there are other types of widely used components also, such as Light Emitting Diodes (LEDs), Inductors, Microcontrollers, Fuses, Relays, etc.

Real life Statistics

Based on our experience of maintaining electronics components database of a reasonably large size (at the moment more than 100000 components), we could come up with these pie chart that confirms our analysis. The database is based on components found in the customer Bill of Material files and properly categorized by human operators. As we can see, Capacitors, Resistors, ICs, Diodes, and Transistors are more than 50% of the total 167 categories in our database.

Most commonly used electronics components Pie Chart