PCB vs PCBA – what do you need to know about them

The definition of PCB Vs PCBA

From small chips to big industrial machines, all of the electronic and mechanical instruments and tools are dependent on PCB and PCBA that create an electrical system to make them operational. When entering the field of circuit board, it is necessary to know the PCB vs PCBA is must-to-know area.

The modern world of electronics considers PCB and PCBA a foundational element because these boards are ideal to make them functional. If we want to study PCB vs PCBA, then we should know these basics.

What is PCB?

PCB, also known as a Printed Circuit Board, is a board on which the map for mounting different components is sketched. This board is made up of fiberglass. It has traces made up of copper that indicates the placement of the components, electricity flow, and connection of the components in a well-managed and controlled manner.

What is PCBA?

The completion of tracing and sketching on a Printed Circuit Board leads us to PCBA, which is known as the Printed Circuit Board Assembly. This involves the mounting of active and passive electronic parts such as resistors, SMD components, capacitors, transistors, transformers, diodes, and integrated circuits (ICs).

This mounting is followed by either of two: through-hole technology or SMT technology (Component’s preparation, Solder paste application, Solder paste inspection, SMD pick & place, Reflow soldering, automated optical inspection, Manuel Assembly, and wave soldering). Once this process is finished, we can say that we have assembled items on a PCB which is called PCBA. Then, the circuit is now prepared for use in the electrical gadget for which it was intended and here PCB vs PCBA distinction starts.

PCB vs PCBA – differences

PCB and PCBA, both are circuit boards that contribute to the functionality of modern-day electronics. The differences under PCB vs PCBA are:

PCB is a board with traces without components, whereas, PCBA is a board with assembled components on it.
PCB is a bare board while PCBA is a finished board.
The time required for the completion of PCB is less than that of PCBA.
Complexity in PCBs is less than PCBAs.
Vacuum packing is used in PCB while compartmental anti-static packing is used in PCBA.

Materials used in PCB production

Materials used in PCB production define strength, durability, versatility, and structural rigidity. The composition is selected depending on the requirement, the desired outcome, environmental considerations, and any other restrictions the PCB would experience. Based on the anticipated outcomes, you should select the PCB material. Following are the materials used:

★ Prepreg

Prepreg is impregnated in the copper layers to provide the required insulation using a dried resin. This helps PCB layer to hold together followed by the stacking of cores on each side of the prepreg.

★ Laminate

Laminates are made up of the sheets of prepreg which functions the same as prepreg i.e. holding the cores together tightly which is followed by the pressure and heat.

★ Solder mask

Solder mask is a protection layer coated on the PCB to shield it from low electrical impedance, oxidation, dust, and other irritants that might cause short circuit.

★ Copper foil

This is one of the important components used in the PCB production. This is used for the proper electrical and mechanical transmission so the signals across the board can do their job.

★ Nomenclature

This indicated the white letters on the PCB structuring. Under PCB vs PCBA, nomenclature helps the manufacturers to work consider component’s positioning effectively.

★ Surface quality
In actuality, a PCB’s surface polish is crucial to the finished result. There are also many options available when selecting the touchup edge.

These must be used in order to maintain and improve soldering and gluing at all levels of integration. Under PCB vs PCBA umbrella, these components are the base of the whole structure.

What are active and passive components on PCBA

◆ Active components in PCB are responsible for the signal transmission (power or energy) like Transistor, MOSFET, amplifier, logic gates, and PCB diodes.

◆ Passive components in PCB, acting as energy acceptor, take energy or power for the active components and utilize it as per requirements like resistor, capacitor, sensor, and inductor.

Types of PCB

There are different types of PCB that can be classified by its layers, substrates, and function.

Classified by layers

If we classify PCB based on the layers, we have three types of PCBs. One is single-layered PCB which is least expensive of all the layers consisting of single copper and glass layer. Other is double-layered PCB which has double layer of copper on the sides of substrate which is followed by double conductive layer. Last one is multilayer PCB which has more layers than 2 that are interconnected with the copper plated holes.

Classified by substrate

There are 7 common types of PCBs classified by the substrate stated paper phenolic substrate, paper epoxy board, glass composite substrate, glass/epoxy substrate, Teflon substrate, alumina substrate, and LTCC board.

Classified by function

Rigid, flexible, and rigid-flex are the three types of PCBs classified by its function. Rigid PCB are solid that we cannot pull out of form or twist. It isn’t adaptable. A rigid circuit board cannot be altered or folded into a different form after it has been produced. Flexible PCB can easily be folded and is less rigid than the rigid PCBs. These forms of PCB may be handled and transported with ease and without any harm because to their transparent plastic and form. Flex PCBs come in single-sided, double-sided, and multilayer varieties. Rigid-flex, as the name suggests, has rigid and flexible substrates that are on the single circuit board.

PCB vs PCBA – steps for producing

Steps for producing PCB

▲ Steps for producing PCB are Step 1: Design the PCB using the software and tools. Address the questions by the team to get efficient and effective with the process. Step 2: Start printing the PCB including the copper inner layers. Step 3: Align the layers. Step 4: Send it for the optical inspection to avoid the errors. Step 5: For the component’s proper assembly, drill the board as per requirement. Step 6: Image and etch the outer layer properly. Step 7: Apply solder mask and silk screen.

Step 8: Finish the production of PCB followed by the final testing and inspection.

Steps for producing PCBA

▲Steps for assembly the parts on PCBA are; Step 1: Component’s preparation Step 2: Solder paste application Step 3: Solder paste inspection Step 4: SMD pick & place Step 5: Reflow soldering Step 6: Automated optical inspection Step 7: Manuel Assembly Step 8: Wave soldering Above mentioned production steps for PCB vs PCBA consider the basic procedure that is carried out by SMT technology (modern as well as widely-used)

Conclusion

Almost every electrical gadget, from LED bulbs to smartphones, uses PCB. Nowadays, the PCB serves as the brain of every electrical appliance. The use of PCBs expands as technology and its applications permeate practically every sector.

This PCB vs PCBA will help the manufacturers understand how exactly these two frameworks differ. Almost every sector seeks robotics through powerful machines, which increases the usage of electronics.

The knowledge on PCB vs PCBA holds great important when entering this field. Their production as well as the basics are differentiated properly in this guide.