What Is the Difference between PCB and PCBA?


PCBs are the foundation of modern electronic devices. Printed circuit board (PCB) and printed circuit board assembly (PCBA) are both important terms in the electronics industry. Both are very essential for manufacturing and designing a complete circuit board.

In this article, we’ll discuss what PCBs and PCBAs are, how they are related, and the key differences between the two terms so you can use them both confidently when placing orders and describing products.

What Is a PCB?

PCBs serve as a mechanical foundation in which various electrical components can be mounted to complete the intended circuit. The boards themselves are made of laminate material, such as fiberglass or composite epoxy, and contain conductive pathways that connect different parts of the board. These pathways are printed or inscribed onto the board according to the predetermined PCB design.

Some of the most common types of printed circuit boards include:

● Single-layer
● Multi-layer
● Rigid-flex PCB
● Flexible
Heavy copper PCB
Multilayer flexible PCB

With all of these different types available, manufacturers and product designers can create a diverse array of electronic displays, standalone devices, and more for consumer, commercial, and industrial applications.

What Is a PCBA?

PCBA (Printed Circuit Board Assembly) is the board obtained after all printing solder paste on the PCB and then mounting various components like resistors, ICs (Integrated Circuits), capacitors and any other components like transformers depending on the application and desired characteristics of the board. A PCBA usually undergoes reflow furnace heating to establish a mechanical connection between the PCB and the components.

Components of PCBA

During an assembling process, an empty PCB board is stuffed or populated with electronic components to form a functioning printed circuit assembly (PCA), or the PCBA. Using through-hole technology, the electronic components become mounted in holes that are surrounded by conductive pads. Using SMT, the components are placed on the PCB to ensure that the pins align with the conductive pads. Where electronic components anchor to either side of the board, the components on one side of the board must adhere to the board by the use of glue before soldering.

A populated PCBA board can be tested using one of the following ways:

With the power off, the board may be inspected visually or using automated optical inspection tool.
With the power off, an analog signature analysis can be carried out. This analysis is referred to as “power-off testing.”
With the power on, in-circuit testing occurs
Finally, a functional test can be done to establish whether the PCB is doing what it has been designed to do.
From the descriptions above, we can determine that the PCBA refers to a processing flow, or the complete circuit board while the PCB refers to an empty printed circuit board with no electronic components on it. Generally, PCB is a bare board while PCBA is the finished board.

Materials Used

The substrate material for PCBs is usually fiberglass, composite epoxy or another laminate material. The conducting material on one or both sides of the board is most often copper. The printed circuits, which are plated or etched onto the substrate according to the design, are also made of copper. The circuits are coated with tin-lead to prevent oxidation. PCBs have contact fingers on their outer edges, which are also coated with tin-lead, as well as other materials, such as nickel and gold, to increase conductivity.

What is the difference between PCB and PCBA?

Printed circuit board

PCB refers to the circuit board, while PCBA refers to the circuit board plug-in assembly, SMT process. One is a finished board and the other is a bare board.

PCB(Printed Circuit Board), Made of epoxy glass resin material, it is divided into 4, 6 and 8 layers according to the number of signal layers. 4 and 6 layers are the most common. Chip components such as chips are attached to the PCB.

PCBA may be understood as a finished circuit board, and the PCBA can be made only after the process on the circuit board is completed.

What Are Each Used For?

Printed circuit boards and PCBAs are used in a wide range of industries such as the:

● Aerospace industry
● Automotive industry
● Medical industry
● Military

PCBs and PCBAs are used in many different electronic devices. Most homes in this country will have at least a few devices in every room that contain a PCBA. Some of these devices include:

● Cell phones
● Computers
● Radios
● Televisions
● Calculators
● Printers
● Lighting systems
● Kitchen appliances
● Laundry room appliances
● Pacemakers
● Medical imaging systems
● Engine management systems
● Telecom towers
● Satellite systems
● Data storage equipment

As you can see, PCBs and PCBAs are used in a lot of industries and devices. It’s clear, then, that without PCBs and PCBAs, we would be unable to operate many different devices.


The main difference between PCB and PCBA lies in the manufacturing mechanism and steps. PCB follows a generic manufacturing system. On the contrary, PCBA design varies according to the requirements of the device manufacturer. The layout is done in software and a machine is used to arrange the components according to the layout.

At Unitepcb, we specialize in the design and construction from single-layer to multi-layer PCBs for a wide range of industries. We can work with you to create a custom solution for your needs no matter how complex. To learn more about our custom PCB capabilities, contact us today.