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You might already know that PCB and PCBA both stand for printed circuit board, but you might not know exactly why these words are so similar. PCBA and PCB are both abbreviations for printed circuit boards, but what’s the difference?
First of all, let’s look at the dictionary definition of PCB. PCB is a printed circuit board. It’s a circuit board in the form of a flat piece of material. It’s used to connect electronic components and provide a path for electricity to flow.
PCBA is another word for a printed circuit board. It’s simply an abbreviation of the printed circuit board assembly.
So, in summary, if you’re looking for something printed circuit board, you’ll want to use a PCB. If you’re looking for printed circuit board assembly, you’ll want to use PCBA.
Is that all? Of course not. We are going to dig out the differences between these two further.
What is a PCB?
Printed circuit boards (PCBs) are specialized circuit boards with copper traces or copper patterns. The copper patterns connect electronic components and enable the flow of electricity.
The PCBs are used in many electronic devices, such as computers, televisions, cell phones, handheld devices, etc. They are also used in many industrial applications where electronics are used, such as power plants and other large industrial installations.
What is PCBA?
PCBA stands for printed circuit board assembly. It’s a printed circuit board with all the components mounted on it. In short, a PCBA is a complete electronic component assembled onto a printed circuit board.
When you need to order a PCBA for your product, you need to specify what type of enclosure you want for your product, and then you can choose a PCBA manufacturer that you want to order from.
PCBAs are used in many different applications, including medical equipment, aerospace, military and automotive.
Different types of PCBs
When it comes to PCBs, we have different variants. The main types of PCBs include:
Let’s look at the key differences between these PCBs.
Single-sided PCBs are the most basic and straightforward PCBs available. They are made of a single layer of copper and fiberglass laminate. Single-sided PCBs come with a single side, which is usually etched to carry the electrical components of the PCB. This type of PCB is not as common as other types, but it is still used for some applications.
Double-sided PCBs are more common than single-sided ones. They are made with two layers of copper laminate and fiberglass laminate sheets on each side of the board. A double-sided PCB has the same features as a single-sided one but with an added layer on both sides.
The advantage here is that double-sided PCBs have better electrical performance than single side ones. For this reason, they can be used in more complex applications than a single-sided PCB board can offer.
Multilayer PCBAs are the most advanced PCBs available. They have the same features as double-sided PCBs but with an added layer on both sides of the board. This gives multilayer PCBAs even better electrical performance capabilities than double-sided boards. Multilayer PCBAs are used in complex applications that require high performance and reliability.
Rigid PCBs are made of thicker copper layers and a thicker fiberglass laminate sheet on each side of the board. Wooden boards offer a longer lifespan than other types, making them suitable for more demanding applications like transportation devices, instruments, and industrial equipment. The rigid construction makes these boards more resistant to external factors like water or temperature changes.
Flexible PCBs are just as standard as rigid ones. They’re made from thinner copper layers and thinner fiberglass laminate sheets on each side of the board. Flexible boards are flexible, making them easy to use in applications that require movement. They’re commonly used in wearables, medical devices, and other applications that require flexibility.
Ceramic PCBs have a ceramic base instead of a fiberglass laminate sheet. This makes them more resistant to chemicals and corrosion than other PCBs. They’re commonly used in devices that need to operate under harsh conditions like military equipment, chemical processing equipment, and oil and gas equipment.
Hybrid PCBs are built from several materials, including glass epoxy laminates, metal layers, and dielectric layers. Hybrid boards can be used for a variety of applications because they offer the best electrical performance capabilities available among all types of PCBs. They’re commonly used in industrial applications where flexibility is needed, but reliability is also required.
What is the PCBA assembly process?
As we have seen, PCBA is an assembled PCB. So, what does the assembly process entail?
It all starts with getting a bare PCB. You must mount the components onto the PCB and then solder them together. After that, you can place the PCB into a housing or case to complete the assembly.
There are three main steps in the PCBA assembly process:
Surface-mount technology (SMT) placement
SMT is a method of soldering electronic components onto a printed circuit board without having to remove any of its protective layers, like an integrated circuit (IC) chip or resistor. For example, some SMT processes use an automated pick-and-place machine that places components in locations on a PCB according to the design files for that PCB. The machine then automatically solders them into place using minimal manual intervention from workers.
Through-hole insertion placement
Through-hole insertion placement is another method of placing electronic components on a PCB. Still, it involves removing some of its protective layers and manually inserting wires through holes in the board so they can attach to other parts inside of the housing or case.
Soldering is the process of melting a metal alloy (a solder) to flow and form a conductive, secure connection between two contacts. The contacts can be two wires, an IC chip, a PCB pin, or two PCB pins. After the solder has cooled, the excess is removed from the connection. This will leave a shiny joint between the contacts.
PCBA and PCB design
The PCB layout process is often called PCBA design because it includes PCB layout and the assembly of components (known as “components assembly,” “parts placement,” or “parts pick-and-place”).
This is done using a computer-aided design (CAD) software package that has specialized features to help automate the process. The final result is a printed circuit board used in electronic devices such as computers, cell phones, video game consoles, and other products.
PCB manufacturing process
After the PCB design is complete, the PCB goes into production. The first step is to produce a photomask from the CAD file using an optical mask writer machine.
This mask contains all the information needed to expose photoresist on one or both sides of a blank PCB substrate sheet. This sheet is then placed into an automated drilling machine that uses the mask to drill holes in each location where there are supposed to be copper traces on the PCB.
The drilling is done by exposing photoresists in the areas that are being drilled and then etching away the exposed material. The remaining areas with no traces are covered in a non-conductive material to protect them from the etchant.
The photomask is then removed, and the substrate sheet is washed to remove any remaining photoresist residue. The substrate sheet is then placed into an automated pick and place machine that will place each component on the PCB in its proper location. This process can be very time-consuming and may require several passes if positioning components such as capacitors or resistors over large areas of the board.
Placing components can be sped up using automated machines known as “pick-and-place machines” (P&P) that use vision systems to place parts on a PCB without human intervention automatically.
PCB and PCBA testing
Circuit board testing is the process of testing a printed circuit board or printed circuit board assembly to determine whether the PCB is functioning correctly.
A variety of equipment and techniques are used to test a printed circuit board. The most common test is using an oscilloscope to measure the waveform output from an electronic component on the board using probes attached to electronic probes. This can be done with a Probe that attaches directly to the component or with an adapter that connects to a socket on the component and then plugs into an oscilloscope probe. Other tests can include measuring voltages, currents, and temperatures using specialized instruments.
There are two main types of testing: functional and environmental. Functional testing ensures that all components are working properly, while environmental testing ensures that all components are functioning within specifications necessary for their intended use on the PCB.
Functional testing typically involves attaching leads or sockets to components (such as through-hole parts) or placing sockets into sockets (such as surface-mount parts). After these connections are made, the component is tested to ensure that it is working properly.
Environmental testing involves measuring voltages, currents, and temperatures across components. This is done to ensure that the component is functioning within the specifications necessary for its intended use on the PCB.
The most critical aspect of testing a printed circuit board is inspecting the solder joints on components. The easiest way to check for proper solder joints is with a microscope, but this requires a very large bench space and can be quite time-consuming.
What is PCBA number?
The PCBA number is a unique identifier assigned to each printed circuit board. The number is assigned by the PCB manufacturer, and each type of circuit board has its own PCBA number.
The PCBA number allows the PCB manufacturer to track the PCBA through its life cycle. The PCBA number allows the PCB manufacturer to trace production and quality problems.
PCBA numbers are also used to identify printed circuit boards in a data center or manufacturing facility. This reduces errors and increases productivity.
So, next time you buy a PCBA, you should check its number. You will use it to refer back to the manufacturer if you need some assistance or when your PCBA develops technical issues.
PCB vs PCBA: What’s The Difference?
Concerning the PCB vs. PCBA, you may encounter the acronym “PCA.” How is it different from these two?
PCB is short for printed circuit board, and PCA is short for Printed Circuit Assembly.
PCB is the base material on which the electronic components are mounted. The PCB insulates the electronic components from the external environment.
PCA is an assembly of multiple PCBs mounted on a printed circuit board carrier or a large piece of plastic that can be placed in an enclosure.
Which components are assembled on a PCBA?
As we have stated, a PCBA is a PCBA that has been assembled and embedded with different components. So, which are these components?
The most common components of PCBA include diodes, capacitors, resistors, transistors, ICs, and coils.
Other than this, there are also power components such as inductors and transformers, which also come in different shapes and sizes depending on their function in the circuit.
What should I look for when buying PCB and PCBA?
Here are some key technical specifications for PCB and PCBA that you should be concerned about;
PCB material: PCB is made of any of the following materials: copper, aluminum, and plastic. The material is important because its properties determine the electrical characteristics of the PCB. Therefore, you need to check whether the PCB is compatible with your circuit.
PCB size: The PCB size depends on which components have been mounted on it. This means that if you are planning to mount many components on your PCB, you must opt for a larger size board.
PCB thickness: The thickness of a PCB also depends on its intended application and usage.
Layers: A PCB has more than one layer. The number of layers depends on the intended application of the PCB.
Weight: The weight of the PCB depends on its thickness and material.
Corrosion Resistance: A PCB has different types of coating on it to make it corrosion resistant. The type of coating depends on the intended application and environment.
Surface Finish: The surface finish of the PCB is also essential. The type of finish depends on the intended application and environment.
At this point, you clearly understand the difference between PCB and PCBA. You can also make smart decisions when buying printed circuit boards. What remains is choosing a reliable brand or supplier.
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