Important Components of the Main PCB Assembly Process

Posted on 2020-06-22

Main PCB Assembly: Beginners Guide to Commonly Used Components

Understanding the main PCB assembly process can be a challenging task, especially if you are not familiar with the concepts. We understand that you would want to venture into the world of PCBs, after all, they have become an imperative part of all modern electronics.

We simply cannot imagine any appliance not using a Printed Circuit Board. So, more and more people are trying to enter the industry, even the ones who have limited information about the Printed Board. In some cases, you might be a student who wanted to learn more about these amazing PCBs.

Regardless of your objective for understanding the basic concepts of the Printed Board, we have come up with an effective beginner-level guide. In this blog post, we are going to talk about the basic components of a PCB.

These components are part of all PCB types. Therefore, learning about these components would provide you with basic information about PCBs.

Main PCB Assembly – Main Components

For a PCB to power the device, it needs to have all its components in the working state. Failure in one component would lead to the failure of the entire Printed Circuit board. This would then result in the malfunctioning of the devices.

So, here are the most commonly used components of a Printed Circuit Board.

Main PCB Assembly


Among the most common components of PCBs, we have resistors. In addition to being common, they are also extremely easy to understand. The main job is to resist the flow of current. In order to do so, they dissipate electric power as heat.

Resistors are available in a number of types. Moreover, manufacturers use different materials for their construction. Every type of resistor has its own advantages and disadvantages. Nonetheless, the classic resistors are somewhat similar to the hobbyist in the axial style resistors.

Both these resistors have color ring bodies and long ends. The rings are basically the code indicating their resistance value.


Next in line, we have the capacitors. We are sure most of you might have heard this word, even if you are new to the PCB concept. Capacitors are used universally, and all appliances incorporate them one way or the other.

In a PCB, there more resistors than there are capacitors. Capacitors are responsible for holding the electric charge for a short period. Then, they release it to the place where it is needed the circuit. Generally, is first collects the opposite charge on two layers (conductive). To sperate the layers, manufacturers use either the dielectric material or insulation.

To categorization of capacitors depend upon either the dielectric material or the conductor. Thus, resulting in a wide range of capacitors offering different characteristics. Some common types include diverse polymer capacitors, capacitance electrolytic capacitors, or the ceramic disc capacitors.


Even though inductors are the last in the linear passive components of the main PCB assembly, yet they do hold great importance. Their main function is to store energy. However, the difference between them and capacitors is that instead of storing electrostatic energy, they save it in magnetic field form.

The current flowing through inductors helps create the energy that they store. The coil wire is perhaps the simplest inductor, you will come across. For a great magnetic field, you need a greater number of windings. Thus, there you are more inductance.

To look for an inductor on a PCB, see its magnetic core. They are wrapped around it. Remember, the magnetic core comes in a number of shapes. In addition to amplifying the magnetic fields, inductors also help in blocking a certain type of signal.

For instance, they are useful for blocking the interference in a radio device.


They are a sort of variable resistors, and you will mostly find them in the linear and the rotary types. To vary the resistance, you would have to rotate the rotary potentiometer’s knob. This would move the slider contact over a semi-circular resistor.

Have you ever noticed the volume controller of an old-style radio, that is the classic example of the rotary potentiometer? The amount of current supplied to the amplifier is controlled by the potentiometer.

There is no difference in the linear potentiometer expect that the contact between moving slider contact on the resistor is linear. They are perfect especially when you want to fine-tune things in the field.

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The main objective of a transformer is to transfer energy from one circuit to another. While transferring, there is either a decrease or an increase in the voltage. In other words, we can say that voltage transformation is taking place.

The appearance is similar to that of an inductor. They have minimum tow coils of wire and a soft iron core.  For the source circuit, the primary coil comes into action. Whereas the second coil is for the circuit where the energy will reach too.

Diodes of Main PCB Assembly

Diodes are like a one-way street. It lets the current flow in one direction. The fixed direct is from anode positive to cathode negative. When it does this, it tends to offer zero resistance in one direction, whereas it has a high resistance in the other direction.

Diodes are effective to prevent the current from flowing into the wrong directions. After all, faulty current flow would damage the Printed Circuit Board. Light-emitting diode or an LED is among the popular diodes that you will find.


Transistors hold great importance for modern electronics. In fact, they are claimed as the fundamental building blocks of compact and sophisticated electronics. There are extremely small, and you can find up to several billion in just a single IC chip.

However, these transistors are no more than electronic switches or amplifiers. Transistors can further be categories into PNP or NPN versions. The basic structure of a bipolar transistor compromises three pins including the emitter, collector, and the base.

In the NPN type transistor, the current flows from the base to emitter, it then turns onto another circuit. Thus, causing the current which is larger to flow from collector to emitter. In the case of PNP transistor, the rule is the same, however, the direction is opposite.

Silicon Controller Rectifier of Main PCB Assembly

Silicon Controller Rectifier, also famous as Thyristors, silicone controller rectifier has similar functionalities as that to a diode or a transistor. In simple words, we can say that they are two transmitters put together.

Like the above, SCR has three leads. However, it has four silicone layers. It also acts as a switch, and not as an amplifier. Moreover, you just need a single pulse in order to activate the switch. This is different from the other similar components.

They work well when you need to switch larger amounts of power.

Integrated Circuits

These are basically components and circuits that are shrunk down onto wafers of the semiconductor material. The circuit is encapsulated into plastic housing. This housing comes in a number of shapes and colors.

Crystal Oscillators

For the stable and precise timing elements, many circuits incorporate the crystal oscillators. They are responsible for generating a periodic electronic signal. To do so, they would physically cause the piezoelectric material to oscillate.

Every crystal oscillator has its own vibrating frequency. In addition, they offer more stability, smaller form factors when it comes to some of the other timing methods. Due to this particular reason, we seem them in quartz wristwatches and microcontrollers.

Main PCB Assembly Summary 

These are some of the important components of the main PCB assembly line. In addition to these components, we have the switches and the relays as well as the sensors. All these components put together to come up with a Printed Circuit Board.

Since a PCB is of great importance, therefore, choosing an excellent PCB manufacturer is vital as well. 6pcba offers the best PCB services from prototyping to assembling and manufacturing. They ensure the highest quality Printed Circuit Boards. These boards will meet all your expectations.