Blog  /  The Most Comprehensive Introduction to PCB Components

The Most Comprehensive Introduction to PCB Components

Printed circuit boards are essential in the manufacturing process of a circuit board. But how do you go about choosing the best manufacturing board components? A lot are standardized off-the-shelf parts that you can fast identify, find, and then purchase. But other details will be more proprietary to your project, meaning that they’ll be more challenging to find. You’ll achieve your PCB assembly process faster if you know the parts that you need.

This article is a systematic talk of what you need when it comes to printed circuit board components. With all the features that you need, rest assured of an easy PCB assembly process.


1. What is a PCB Component?


A printed circuit board component is an electrical part that goes into making the entire circuit board. PCBs consist of electrical elements such as diodes, capacitors, fuses, and resistors. For a PCB to function effectively, each component must play its role. If one part fails, then the PCB may fail to function as intended.


PCB components

(PCB components)


2. PCB Components Identification


PCBs are ubiquitous when it comes to almost all electronic components. When designing PCBs, the ingredients that go into the entire PCB design matters a lot; as a designer, the following are what you may need to keep at the back of your mind when it comes to PCB components identification.


   2.1 First, determine the printed circuit board or PCB


The first thing that you need to do is to determine the PCB that will suit your project. There are several types of PCBs. Does your project require flex, rigid, or rigid-flex PCBs? You need to choose the right PCB suitable for your project.


   2.2 Identify other “nut and bolt” electronic circuit components


As a designer, you’ll have to fasten your PCBs. When it comes to fastening, you’ll have to choose between nuts and bolts. Bolts come in different length sizes, but nuts have a standard size. Again, depending on where you intend to use your PCBs, you may be forced to choose between nut or bolt fasteners.


   2.3 The battery, fuse, diode, and transistor of the circuit board


A shower, diodes, fuses, and transistors are essential elements on a PCB. A battery powers the entire PCB. A transistor amplifies the charge. A diode allows current to flow in one direction while blocking the other. A fuse breaks if too much current flows in a circuit.


   2.4 One or more processors


PCBs require processors. Processors play an essential role in receiving input and providing the appropriate output. Depending on the PCB part, you may have to include more than one processor on the PCB. Modern PCBs include several processing cores that work in unison to process instructions.


   2.5 Connectors on smaller circuit boards (especially on the motherboard)


PCBs need connectors. Connectors are small electronic devices that easily and quickly interrupt or disconnect a circuit path. Connectors do come in a variety of shapes, sizes, quality levels, and complexities. The most common connector types are one-piece card edges and two-piece board-to-board. One-piece card edges are the ideal type for small circuit boards.


   2.6 Other chips on the circuit board


There are plenty of components that go into the manufacture of printed circuit boards. These components are also known as chips. When designing a PCB, there are many chips required besides diodes, transistors, fuses, and diodes. Other chips that go into PCBs manufacture include capacitors, LEDs, copper, and potentiometers, to mention but a few.


   2.7 RAM (Random Access Memory) connection position on the circuit board


RAM is a memory of a device. It’ is the “random access” because you can access any memory cell directly provided you know the column and row that intersect at that cell. On the circuit board, the connection position of the RAM matters a lot. For the best operation, RAM needs to be adjacent to the CPU socket.

Several PCB components on an isolated white background

(Several PCB components on an isolated white background)


3. PCB Components List


Without details, a PCB is nothing but a bare board. A PCB consist of several parts, such as the ones highlighted below:

Resistor – PCBs have resistors in them. The primary function of resistors is to control the flow of current to other parts of a PCB. Resistors are thin, rectangular plates or polyester film. A majority of them are tan or blue, though they are available in a few other colors.

Capacitors – capacitors play an essential role in storing electrical charge. They come in large cylinders or little disk-shaped gumdrops.

LED – a light-emitting diode is a crucial component that gives off light. It’s a necessary part of a PCB and available in single, multi-color, high and low-power varieties. Single color and low-power LEDs are the most common.

Transistor – transistors are semiconductor devices whose role is to switch or amplify electronic power and electronic signals. You can identify transistors by their three terminals in addition to their “D” shape. On a PCB, Q is often the indication of transistor locations.

Inductor – inductors store electrical energy in the form of magnetic energy. It’s a little bit difficult to identify inductors. On a PCB, you can find inductors either as color-coded or raw wired coils. Fortunately, PCB designers use L to indicate an inductor.

Diode – a diode is more of an electronic version of a check valve. The diodes’ primary function is to allow electric currents to flow in one direction while blocking it in the opposite direction. Diodes are highly essential on a PCB.

Integrated circuit – integrated circuits function as oscillators, amplifiers, timers, or a memory. Integrated circuits are small wafers, usually made of silicon. They have the capability of holding hundreds to millions of resistors, capacitors, and transistors.

Transformers are transformers composed of two coils, whose core function is to reduce or stop the power supply.

Sensor – some of the primary parts of sensors measure features such as pressure, light, or sound. Sensors convert measurable physical actions to electrical equivalents. It then processes them so that that the electrical signals get processed.

Potentiometer – mostly, potentiometers are used for purposes of measuring electrical voltage or potential. Potentiometers are usually marked in ohms by use of three digits. The initial two numbers indicate the significant figures, with the last proving the power of 10 multipliers.

Crystal oscillator – Oscillators have marks on boards with letters X and Y. These devices are essential in ensuring that electronic devices work correctly and on time. Their unique appearance makes them easy to identify. Better yet, they have specifications written on them.
Switches and relays – PCBs consist of switches and relays.

Regulators play an essential role in interrupting current. On the other hand, relays play the role of shutting power on and off.

Silicon Controlled Rectifier (SCR) – a Silicon Controlled Rectifier (SCR) is a semiconductor switch. The primary part of this device is to control large amounts of power using small signal inputs.

Passive device guide – PCBs contain passive devices. The primary function of passive devices is to store or dissipate energy. Of importance to note is that such devices do not generate power. They just store energy and include components such as inductors, resistors, and transformers.

Wire – wires are essential in a PCB. The primary function of cables is to allow the flow of electricity from one component to the next. In short, wires carry the flow of electrons.


Resistors, anodes, and transistors on a PCB

(Resistors, anodes, and transistors on a PCB)


4. PCB Component Layout you Need to Know the Electronic Circuit


A PCB layout means transferring a course from a breadboard to a permanent and stable physical condition in its most basic form. There are several categories, elements, and types of electronic circuits, as highlighted below.


   4.1 Categories of electronic circuits


Active components – Active components do rely on energy sources in the system. Active sources have the capability of inducing power to the circuit.

Passive components- Passive components cannot introduce energy into an electronic circuit. They don’t rely on DC sources of power like the active components, meaning that they cannot amplify signals.


4.2 Electronic circuit elements


The following are elements of electronic circuits worth noting. On a PCB, the following are some of the essential electronic circuit elements that you need to know:

Electron current – Electron current is the flow of electrons. On a circuit board, electrons do flow from negative terminals to positive terminals. Conventional wind behaves as a positive current to cause the flow of current.

Power source – When it comes to a power supply, an important thing that you need to choose is the type of power source that is ideal for your device. Depending on where you intend to use your device, you may choose between AC and DC input.

Load – An electric load is more of an electrical component that consumes electric power. It’s different from a power source, such as a generator or battery that produces energy. Lights and appliances are examples of loads on a PCB.


4.3 Types of electronic circuits


There are several types of electronic circuits. Some of the main ones include the following:

Direct current – In a Direct Current electronic PCB, electricity flows in only one direction. Smaller PCBs typically rely on direct current.
Alternating current – In an Alternating Current PCB, electricity flows in both ways while switching periodically. AC is easy to produce, not forgetting that it can cover long distances without energy loss.

Series circuit – A series circuit PCB involves linking components one after the other in a loop. The connection between elements is through single terminals only. A breakage in the link ultimately leads to the failure of the entire circuit.

Parallel circuit – Unlike series circuits, parallel circuits PCBs involve the placement of components in separate branches. In parallel circuits, the link between parts is through both ends, but in different chapters. If there’s a breakage of relationship in a parallel circuit, only the branch with damage is affected.


A close pic of a high-tech PCB

(A close pic of a high-tech PCB)


5. How to Choose the Right PCB Components


Circuit boards may seem somewhat incomprehensible, but its components matter a lot. The functioning of a PCB depends on its members. So, how do you go about choosing the right PCB components? Here’s what you need to do.


5.1.0 PCB design


Choose suitable components – For the best functioning PCBs, you need to select the right parts for your board. Go for the best materials that will suit your board. Ensure that your diodes, anodes, and transistors are of the highest quality.


5.1.1 Use schematics to plan your project


Schematics are of importance when designing a PCB. With the help of schematics, you will be able to better position. To know where every PCB will fit and how to maintain and repair your PCB in case of damage.


5.1.2 Required space element/component size


What’s the size of your electronic component(s)? If it’s too large, then you may require a giant board. Still, you may need larger components on your PCB for better functionality.


5.1.3 Consider component footprint


Your PCB component footprint has to include important pieces of information. Things such as assembly, placement, and part numbers are invaluable and need to be present in a component footprint. When creating a PCB footprint, make sure that you keep your entire datasheets handy. Also, understand the standard package sizes, and watch for through-hole sizes and locations.


5.1.4 Follow acceptable grounding practices


When designing a PCB, you need to stick to some grounding rules. Grounding is essential in your design process. Without a stable ground, you may not be able to ensure the passage of clean signals from one component to another. Some essential grounding practices involve leaving nothing unattached, grounding before routing, and minimizing series vias.


5.2 PCB soldering-choose right components


PCB soldering may seem to be a straightforward step, but you may end up with low board if you do it wrongly. If you desire to have a good board, ensure that you go for the right equipment. Make sure that the soldering iron and the solder itself are of the highest quality. If you employ the wrong components, you may end up with a printed circuit board that won’t serve you properly.


5.2.1 Separate lead from lead-free components


For many years, leaded solder has been a popular go-to substance in rework and electronic manufacturing. But in the last few decades, there’s been a growing concern for an environmental and increasing problem with products made using lead. The choice between leaded or unleaded components depends on the size of your project.

However, due to the latest government directives, you may have to go for unleaded components. Lead-free components are known for being environmentally friendly and not hazardous to humans.


5.2.2 Do you need padding


A PCB pad is the exposed surface of a printed circuit board where components get mounted and soldered. Pads consist of different styles and shapes, depending on components soldered to the place. Padding avoids flashovers and tracking that may occur between electrical conductors.


5.2.3 The pad design matches the lead setting on the component


This is simple. The pad design needs to match the lead on the part. As much as possible, ensure that the pads match the lead settings to avoid imbalances in the solder joints.


5.2.4 Consider component packaging options


You need to select a component package with the ability to add some touch of perfection to your overall design. With an excellent components package, you’ll improve your image as a proficient PCB designer. A useful components package supplements your aesthetics design and attracts more customers.


A correctly assembled PCB

(A correctly assembled PCB)


6. How to Solder PCB Components


Soldering involves using a filler material, also known as solder, to join some metal pieces together. Soldering takes place at relatively low temperatures compared to welding and brazing that require high temperatures.


6.1 Solder PCB components


To solder PCB components, you’ll need the right equipment and a clean working surface. You begin the whole process by placing pieces into the holes. You need to ensure that you place the components so that the legs effectively come out on the same side as the solder pads. On the PCB solder side, make sure that you carefully bend the legs of components a bit. By doing so, it will not fall out if you flip the board upside down. In short, when soldering components on a printed circuit board, make sure that you have the right tools for the job. Work on a clean surface while ensuring that you follow all the steps. Don’t forget to keep all the safety precautions to don’t injure yourself or your colleagues.


6.2 How to place components on PCB


Placing components on a PCB isn’t a difficult task. First, you have to group the elements by function. Next, you need to keep the details away from the dissipating area. After that, make sure that you place the board-to-wire connectors near the edge. After that, get the orientation of the components standardized before finally making space for copper traces.


6.3 How to remove components from PCB


Removing parts on a PCB is an easy three-step process. First, you need to inspect the size of the solder joints on the role that requires removal. Next, you need to apply a small amount of liquid flux to solder joints of features you want to remove. Lastly, carefully place a heated soldering iron tip on the board’s component side's lead to remove the part (s).


PCB soldering

(PCB soldering)


7. Can the PCB Components Age?


PCB components can age. However, there are several reasons as to why printed circuit components age as discussed below. When something goes wrong during the manufacturing age, PCBs can age within a short time. Still, printed circuit boards can age after being in use for a very long time.


7.1 Why do PCB components fail because of old age


PCBs can fail due to old age. After functioning for a very long time without replacement, PCBs age. Because of old age, printed circuit boards will not function properly. After some time in service, there’s a need to replace printed circuit boards or printed circuit boards components. Diodes, transistors, and transformers need replacement after a long time in service. The average functioning time of these is close to 10 years. After a decade of working, such components may need replacing.


7.2 How to prevent the aging of PCB components


There are several ways of controlling the aging of printed circuit board components. While it’s hard to avoid the failure caused by age, the costs of replacing parts are controllable. As a designer, you can avoid such costs by swapping old components for new ones. If you want to prevent PCB components’ aging, ensure that you use quality materials during PCB manufacture. Also, ensure that you correctly place your details and avoid the usage of burned components. If you use burned components, then they will age within a short time.

Much worse, if you place your details poorly, they will age within a short time. If you want to avoid rapid aging, make sure that you employ the best soldering techniques. Make sure that you avoid matters to do with chemical or fluid leakage during soldering.


A picture of an aged PCB

(A picture of an aged PCB)


8. How to Order PCB Components


Based on the increase in the demand for electronic components, getting PCB components that meet your needs has to be easy. Before ordering the right parts, you need to take some time to determine if they’ll meet your needs. The components that go into your printed circuit board will decide on its overall functionality. Before ordering PCB components, you need to look at different manufacturing options. Depending on the size of your project, you may require either small or large quantities.


8.1 Channel selection


When you want to order your PCB components, you must ensure that you select the best supplier. Channels selection involves the identification of the most reliable suppliers. It also involves getting to know whether prospective members are suitable. Lastly, channel selection involves securing prospective suppliers for the channel.


8.2 Correctly recognize the manufacturer’s part number (MPN)


A manufacturer part number is an identifier of particular part designs used in a given industry. The primary purpose of a manufacturer’s part number is to simplify the reference to that specific part. A part number does identify a part design within single or several corporations. The easiest way to determine the manufacturer’s part number is on the product itself. If you cannot find it on the product, you can find it on the invoice. When selecting PCB components, you need to ensure that they come with the manufacturer’s part number. A manufacturer part number enables you and your manufacturer to reference and identify parts quickly. Additionally, MPN ensures that your manufacturer can quickly process design revisions with a little chance of error.


8.3 Quantity ordered


Quantity ordered refers to the overall number of stock-keeping units that you request from a supplier. These units aren’t counted as part of the quantity on hand till they arrive. Getting to know the amount to order is essential as it will prevent the duplication of orders of the same items. The same is true when it comes to PCBs. As a PCB designer, you need to know the number of components to avoid parts duplication.


8.4 Avoid parts mismatch


When ordering PCBs, there’s nothing worse than being supplied with parts that don’t match. Components mismatch is one of the worst things when it comes to PCB assembly. If you want to ensure that you avoid parts mismatch, make sure you have a missing aperture list and a missing drill file. Also, ensure that you have a missing Gerber file and a missing tool list. With all these files, you’ll boost your chances of minimizing parts mismatch.


8.5 Consider the expected cost issue


Ordering costs are the expenses that you’ll incur to create and process your order. When it comes to ordering components of a printed circuit board, you need to factor in the expected costs. If you bump into a cheap manufacturer, then probably, their products aren’t of high quality. You need to ensure that the value of the product matches its quality.




Printed circuit boards are the basis of almost all electronics and technology in the world. There are different types of circuit boards, all suitable for the project at hand. Are you looking for the best PCB? We have been one of the best PCB suppliers for more than ten years.

We always hope to exchange more information and knowledge about the PCB with you. To get the best results for your PCB project, get professional advice on copper weight, material selection, component selection, etc. You can get in touch with us by mail, and we can discuss and solve your current difficulties together.