In electronics, the terms printed circuit board (PCB) and printed circuit board assembly (PCBA) are very related. Some people use them interchangeably, but they are not the same thing.
The main difference between these two designations is that PCB refers to a blank circuit board, while PCBA refers to a circuit board with all the electrical components. The PCB isn’t functional yet because it’s missing the necessary components, but the PCBA is a complete working board. PCB and PCBA are two different stages in the same process,PCBA builds on top of an existing PCB.
In this article, we will understand the definitions of PCB and PCBA, and the difference between these two terms.
What exactly is a PCB?
PCBs are the cornerstone of modern electronics. They provide mechanical support and electrical connections for electronic components. These boards consist of laminated materials such as fiberglass or composite epoxy, with conductive pathways connecting the various components of the board. These paths are printed or engraved on the board according to the PCB design.
PCB subtype
PCBs are divided into three categories:
A single-layer PCB is the most basic PCB, with a single layer of conductive material and a layer of solder mask. Silkscreen is used to identify components on the PCB.
Two-layer printed circuit boards (PCBs) contain a layer of conductive material on both the top and bottom of the board, allowing them greater flexibility and smaller size than single-layer PCBs.
Multilayer printed circuit boards (PCBs) contain more than two conductive layers for more complex applications.
Flex PCB, rigid PCB and rigid-flex PCB are also popular forms of PCB.
Materials used
PCB substrates are usually made of fiberglass, composite epoxy, or other laminated materials. Copper is often used as a conductive material on one or both sides of a circuit board. Copper is also used in printed circuits, where it is plated or etched into the substrate depending on the design. To avoid oxidation, the circuit is covered with tin-lead. To improve conductivity, the PCB includes contact fingers on its outer boundaries, which are covered with tin-lead and other materials such as nickel and gold.
What does PCBA mean?
A PCB is a blank board while a PCBA is a complete PCB assembly that has all the electronic components needed to make the board function properly. The process of building a circuit board with the proper components is sometimes called a PCBA.
PCBA companies can use one of the following two methods for PCB assembly:
- Surface mount technology
Surface mount technology (SMT) is an assembly method that involves attaching electronic components to the surface of a printed circuit board (PCB). It is highly automated and multifunctional, allowing for increased connection density. It allows manufacturers to incorporate complex circuits into tiny components.
The four basic stages of PCBA SMT are:
Apply solder paste: First, the assembler applies solder paste as needed to the PCB board.
Component placement: The assembler next inserts the components into the board, usually with the help of a pick and place machine.
Reflow soldering: The board is then heated in a reflow oven until the solder paste reaches the temperature required to form a solder joint.
QC Inspection: Throughout the SMT process, assemblers inspect components before they are connected and before and after reflow soldering.
- Through hole technology
Through-hole technology is an assembly method that involves drilling holes in a PCB to connect electrical components called leads. Although it is an older technology than SMT, it creates a stronger connection between the board and the component, resulting in a more durable and reliable assembly.
Through-hole assembly can be fully or partially automated. The stages of the PCBA through-hole procedure include:
Hole Drilling: Drilling holes in the board is the first step in the through-hole method. The holes must be large enough to accommodate the component leads.
Leads Placing:The assembler then inserts the component leads into the holes.
Soldering:Welding is the next stage in the process. This step ensures that the components are securely fastened.
QC Inspection: Throughout the process, components are inspected to ensure the PCBA is functioning as planned.
What is the relationship between PCBA and PCB?
PCB and PCBA are two separate stages in the same overall process. A PCB is a blank circuit board without any electronic components connected to it, while a PCBA is a finished assembly that includes all the components necessary for the board to function properly for a specific purpose. The PCB is not yet functional, but the PCBA is ready for electrical equipment.
Since different components and procedures are required for PCB assembly, it is simpler to produce a blank board than to produce a complete PCBA. A PCBA is also more expensive to build than a blank PCB. However, both stages require the production of finished boards. A PCBA cannot be created without a PCB. The first stage of the process is PCB fabrication and the second stage is PCBA production.
Another difference is the packaging method of PCB and PCBA. PCBs are usually vacuum-packed, while PCBAs require compartments or anti-static packaging.
Our PCBA Services
Yingstar Electronics offers skilled PCB assembly services such as board-level and full-box assembly, SMT and through-hole technology, and everything from fully automated processes to Yingstar’s precise hand assembly. And our ISO 9001 certified factory is located in Shenzhen, Mainland China.
When you work with Yingstar, you can expect years of experience, prompt service and flawless products. To learn more about how our PCB assembly services can help you achieve your goals, please contact us at RFQ@yingstarpcba.com.
