In an electrical system, an electronic circuit plays an integral role. For circuit manufacturing and designing, printed circuit board (PCB) and printed circuit board assembly (PCBA) are widely used.
Most of the time, we use both boards for the same purpose. But, both PCB and PCBA are literally two different things and come with different specifications.
In this article, we are going to study the difference between PCB and PCBA. Also, I will explain the definition, working principle, types, specifications, advantages, and applications.
Let’s dive in.
What is a PCB and how does it work?
The PCB stands for the ‘Printed Circuit Board’.
The board consists of alternating layers of conductive and insulating materials to make a complete electric circuit (in the form of circuit tracks). It looks like a laminated sandwich of the conductive and insulating layers.
For designing circuits of electrical and electronic devices, PCB plays an integral role. It provides a conductive track and allows connection between different electronic components over the board.
Different types of PCB are designed as per the application requirement and circuit demand.
If you are interested in circuit designing, manufacturing, and automated assembling, you can use Electronic Computer-Aided Design (ECAD) software along with a PCB board.
Common Types of PCB
There are different types of printed circuit boards. Let’s see one by one.
Single-sided printed circuit board
A single-sided printed circuit board has simple construction. It is built by the single layer of the conductive material (usually use copper materials) and the layer of solder mask.
This type of PCB is widely used in domestic electronics applications such as camera systems, printers, radio equipment, calculators, etc.
Double-sided printed circuit board
The double-sided printed circuit board contains the two layers of metal conductive materials which is placed on the top and bottom of the PCB.
The double-sided PCB gives good flexibility. You will find it in compact size as compare to the single-sided PCB. It is used in commercial and industrial applications like as converter, printer, vending machine, UPS system, amplifiers, control relay, automotive dashboards, line reactors, etc.
Multilayer printed circuit board
The multilayer printed circuit board has more than two conductive layers. This PCB is used in the multi-tasking applications. You will find it in compact size in light weight electronic applications.
For the Computer, Satellite, Atomic accelerators, Fiber optic receptors, nuclear detection system, GPS application, Multilayer PCB is essential.
Rigid printed circuit board
The rigid printed circuit board consists of the multiple layers and sides. And it can be found in a single sided or double sided or multilayer sided.
This board is made of solid, rigid substrate materials (like fiberglass). So, this board cannot be bent. It is not so flexible. For the same reason, sometimes, the rigid printed circuit board is known as an ‘Inflexible printed circuit board’.
The motherboard is the as best example of a rigid printed circuit board.
Flex printed circuit board
The flex printed circuit board (FPCB) can be constructed in three ways such as single-sided, double-sided and multilayer form. In other words, these are the examples of Flex printed circuit board.
The FPCB is used to restore heavy or bulky wiring in superior gear where weight and space matter. It is widely used in modern portable electronics devices, satellites, hard disk drives, desktop printer, etc.
Rigid-flex printed circuit board
The rigid-flex printed circuit board consists of the flexible and the rigid based materials. The multiple layers of flexible boards are attached to the one or more rigid boards (in the form of externally or internally structure). Mostly, its construction is depending on the design of the application.
Rigid-flex PCB can be designed in 3D space applications. It has more advantages over the rigid PCB.
Which is the material used in PCB?
In the printed circuit board (PCB), different types of material are used for substrates and components.
The substrate material for PCB is usually made up of fiberglass, composite epoxy, and other laminated materials.
Listing is the most popular material which are widely used in the fabrication of PCB:
- Flame retardant (FR) (for example, FR-4A1, FR-4A2, FR-4A3, FR-4AB, and FR-4B)
- Composite epoxy materials (for example, CEM-3)
- Polyimide laminate
- Teflon laminate and bonding plies
- Flexible laminates (for example, polyimide and liquid crystal polymer (LCP) or polyester and PEN)
- Other common laminates (like as BT, cyanate ester, ceramics,)
Each material has specific features, functions, and uses. The selection of materials depends on the requirement of the applications. And also depends on the electrical, dielectric, mechanical, and thermal properties of those materials.
Advantages of PCB
- Printed circuit board (PCB) has compact in size. So, you can handle and transport it very easily.
- It requires less wiring. And the cost of PCB wiring is very economical.
- This type of circuit creates less electronics noise.
- In the PCB design, there is very little chance to remove the connecting components or to find short circuit condition.
- In case any fault occurs in PCB, you can check the fault condition and replace the particular failure components easily.
- In the PCB, electronics components are properly assembled and fixed. So, you can easily identify and maintain the PCB’s components.
- The location of the electronic part is fixed and it is easy to simplify components identification. Because of this, the maintenance of equipment is easy for you.
Applications of PCB
Here is the listing of some domestic, commercial, and industrial applications where PCB is very essential and beneficial.
- Printed circuit boards are used in nearly all domestic electronic products such as clock, watch, VCD, DVD, toy, game console, and other electronic devices.
- For industrial purpose, It is used for the manufacturing the industrial measuring and testing applications, switching boxes, industrial automotive circuits (for example robotics, industrial IoT), etc.
- In an aerospace sector, the PCB is used for powering, monitoring, controlling and communication.
- PCBs are used in safety and security applications such as security cameras, smoke detector, automotive door lock, burglar alarms and other indoor and outdoor applications.
- The military and defense uses PCBs for different applications, radio communications equipment, computers, vehicles, firearms and controlling systems and much more operating equipment.
- PCB is very essential for monitoring and controlling the marine appliances such as marine vessel and system, large cargo ship, submarine, communication system, navigation equipment and other systems.
What does PCBA stand for?
PCBA stands for the ‘Printed Circuit Board assembly’. Sometimes, it is known as a ‘Printed circuit assembly (PCA)’, or PCB assembly (PCBA).
The electronic components (i.e. resistors, capacitors, IC, etc.) are attached to the blank PCB board, resulting in ‘Printed circuit board assembly’. And this process is called PCB assembling.
There are two basic ways you can assemble or manufacture the PCB.
PCBA manufacturing process
1. Surface-Mount Technology
The surface-mount technology (SMT) is the PCB manufacturing process which contains the electronic components on the surface of PCB. We can connect components on both sides of the PCB board.
This technology works on automation that helps to place complex circuitries into small components.
This assembly process has more advantages such as require less time for more productions, provide good flexibility, reduce the labor cost and many more.
2. Through-Hole Technology
The through-hole technology is an older type of PCB assembly process.
This assembly process mainly happens into two ways. One is to involve the drilling holes into the PCB and another is to mount the electronic components by leads. The lead inserts through holes on the surface of PCB board and solder onto copper traces on the other side of PCB.
Thus, this technology can be done either fully automated or semi-automated.
It has some advantages over the SMT manufacturing process such as it creates a stronger connection between PCB and the connected components, provides good durable, and reliable assemblies.
With this, you understand the basics of the printed circuit board (PCB) and printed circuit board assembly (PCBA).
What's the difference?
- PCB is bare electronic board which does not contain the electronic components. While, PCBA is electronic board along with electronic components mounted on PCB board.
- Due to lack of electronic components, PCB is not a functional board. Other hand, PCBA is functional board that can be easily operated in any electronic devices.
- For the transportation, PCB requires vacuum type packaging and PCBA requires the anti-static type packaging or compartmental type packaging.
- Due to functionality and presence of additional electronic components, the cost of PCBA is more than the PCB.
Summary
Hope you understand the basic difference between PCB and PCBA. Both are essential for manufacturing a complete circuit board. Without the PCB, you cannot manufacture or assemble the PCBA. We have also seen the applications of PCB and PCBA in domestic appliances, commercial and industrial equipment, etc.