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Circuit Board Parts – The Most Comprehensive Introduction Is Here

Circuit Board Parts are very important in a complete circuit board manufacturing process.

But do you often encounter the question?

How to choose the right Circuit Board Components?

You can quickly identify, find, and purchase many standardized off-the-shelf parts. 

Other components are more proprietary to your project, making them more difficult to find. 

You can do PCB Assembly much more easily after knowing the needed parts.

In this next article, I will give you a systematic talk.

Let’s get started!

1. Circuit Board Components Identification

All electronic devices consist of several different parts. These parts work together to modify and manage current and voltage to produce the desired effect.

Circuit boards act as backbones, keeping everything connected and compacted in an easy-to-use form.

Most of these components are standardized off-the-shelf parts that you can quickly identify, find, and purchase with easy-to-understand shapes, sizes, and colors.

Other components are more proprietary to your project, making them much more difficult to find.

An excellent schematic diagram can help you identify the needed parts and when.

These drawings provide a snapshot of your circuit using symbols representing each component type. Straight, solid lines mark the wiring and connectors between components. Zigzag lines represent resistors. Capacitors are short parallel likes and so forth. To learn more about customizing the harness, check out the following article: Harness: The Ultimate Custom Guide.

A functional schematic also labels each component’s position on the circuit using letters and numbers. For instance, the eleventh resistor is “R11” on the schematic.

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Figure 1: Standard PCB Rapid Prototyping. 3D PCB Printing not only makes the PCB but it also does the Printed Circuit Board Assembly

Circuit Boards

The circuit boards themselves are simple enough. They are just thin plastic rectangular plates or polyester film. Most are blue or tan, though you can find a few other colors as well.

Regardless of the color, new boards have one or more layers of conductive copper foil.

Most boards will only have this foil on one side, but you may encounter double-sided PCBs on occasion. Some professionally made PCs may have many layers of copper.

Either way, you must use particular etching solutions to turn the foil into your circuit’s wiring.

However, you can buy pre-etched boards and skip this step altogether. You need to get the right-sized board for your needs and case.


Resistors limit the flow of current through a circuit. These small, horizontal cylinders often bear four or five colored stripes that help identify their resistance and tolerance.

Larger resistors may also have this information written on them.

Their schematic systems can also print this information in words. In either case, PCBs use R to note resistors.

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These variable resistors are usually marked in ohms using three digits. The first two digits are the significant figures, with the third proving the power of 10 multipliers.

Potentiometers also have a letter code to indicate the resistance change and a VR for variable resistors marked on them somewhere.

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Capacitors store electric charge. They come as small disk-shaped gumdrops or large cylinders.

In either case, the information is printed directly onto them. PCBs use C to make capacitors.

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Connectors are how your device connects to other devices and boards in the same machine. These components tend to have plastic shells and one or more pins that serve as the links between your device and the cables.


Diodes are one-way electrical components with a band that indicates the current direction.

Their specs are on their shells. You may also encounter LEDs and Zener diodes.

Diagrams use an arrowhead and a bar to indicate diodes, while circuit boards use D or CR—the arrow points in the current direction.

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An LED, or light-emitting diode, is a component that can give off light. You can find them in single and multi-color and low and high-power varieties.

Low-power, single-color LEDs are the most common. They often come in their respective colors, but not always.  

They will only have two terminals, a cathode, and an anode. Multi-color ones have more than one color and a set of terminals for each color.

High-power LED has a large metal casing to dissipate the extra heat. LEDs use the diode symbol on diagrams.

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Relays are electronic switches. Powered relays are open, while disconnected relays are closed.

These components typically have plastic shells with their specification written on them. Most boards use “K” to label relays. 

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Transistors are a particular type of switch. You can identify them by their three terminals and “D” shape. Circuit boards often use Q to indicate transistor locations.

Transistor diagrams are circles with three leads. Inside the circle, one point goes directly to a bar, while the other leads branch off diagonally from the bar, one of which contains an arrow.

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 Essentially loops of wire, inductors are often difficult to identify. You can find them either as a raw wired coil or color-coded.

In either case, you should test the components before using them. Fortunately, PCBs use an L to indicate an inductor.

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Crystals and Oscillators

Marked on boards with an X or Y, these natural clocks keep our electronic devices working smoothly and on time.

The unique appearance of a crystal oscillator makes these components the easiest to identify. They also have their specification written on them.

Integrated Circuit (IC)

These complete circuits-on-a-chip will take some effort to identify correctly, as several types of ICs can come in the same package. 

Marked as U or IC on most circuit boards, you often need to look up the device’s datasheet to find the information.

Datasheets offer schematics of devices and are typically found online. Circuit diagrams use rectangular blocks to represent these components.

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2. Common PCBA Components

Most PCBs don’t have every type of component. Most circuits only need a handful to work, with each circuit requiring different components.

Still, there is some overlap, and there are a few common fractures on every circuit board you build.

These common PCB Rapid Prototyping.

2.1 Ball Grid Array (BGA)

Ball Grid Array (BGA) refers to a particular type of surface PCBA used to permanently mount devices, such as microprocessors, to printed circuit boards.

A BGA has some advantages over other methods, and as such, it has become a favorite technique for manufacturing integrated circuits and electronic devices.

A common form of electronic manufacturing is ball grid arrays derived from pre-existing pin grid array (PGA) technologies.

Instead of utilizing pins to conduct electrical signals from the circuit board, a ball grid array uses tiny drops of solder.

These solder balls are placed evenly apart on the board in an array or regular grid and gently heated in a specialist oven. Surface tension ensures that the components are kept in position.

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2.2 Quad Flat No-Lead (QFN)

The QFN (Quad Flat No-lead) package is probably the most popular semiconductor package today for four reasons: low cost, small form factor, and excellent electrical and thermal performance.

Like any other semiconductor package, a QFN package connects (both physically and electrically) silicon dies (the ASIC) to a printed circuit board (PCB) using surface-mount technology.

QFN is a lead frame-based package, also called CSP (Chip Scale Package).

It allows users to view and contact leads after PCBA.

The QFN can have a single or multiple rows of pins. A punch singulation forms the single-row structure, or a saw singulation process divides a broad array of packages into individual packages.

The multi-row QFN uses an etching process to realize the wanted number of rows and pins; these are also singular, typically by a saw.

The benefits of choosing the QFN packages include a decreasing lead inductance due to optimally short bond wires, lightweight, thin profile, and small-sized “near chip-scale” footprint.

Moreover, thanks to the exposed copper die pad, the QFN is perfect for many new applications that need better size performance.

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2.3 LPKF

The solder resists with LPKF ProMask and PCB Rapid Prototyping. 3D PCB Printing not only makes the PCB, but it also does the Printed Circuit Board Assembly (PCBA prints with LPKF ProLegend.

Solder Resist Masks, and PCBA Prints for In-House Prototyping Solder resist is a fundamental requirement for soldering certainty, especially for SMT.

The LPKF ProMask can quickly and effectively apply professional-quality solder-resist masks to structured PCBs.

The solder resist mask is printed onto transparency from the CAD program, transferred onto the PCB, and developed.

In four simple steps, the structured PCB is given a perfect surface finish for soldering without short circuits. This is PCB Rapid Prototyping.

3D PCB Printing not only makes the PCB but also does the Printed Circuit Board Assembly (PCBA print uses a similar process.

ProMask and ProLegend include all the tools and materials required for perfect results.

LPKF ProMask and LPKF ProLegend are essential tools for quick, easy, inexpensive PCB prototyping or small batches.

A photo-optical exposure process transfers all structures or legends onto the PCB in just a few steps.

LPKF ProMask and ProLegend Provide Professional Finishing in Four Simple Steps:

1. Print photo template

The photo template with the desired layout is printed onto a transparency using LPKF CircuitPro and a standard laser printer.

2. Apply paint

Mix the solder resist from the pre-proportioned paint and hardener.

Apply the solder resist onto the structured PCB with the included roller.

The PCB is then pre-dried in a convection oven for 10 minutes.

3. Expose photo template

Position the photo template on the PCB and place both in the UV exposure.

Activate the laser setter for 30 seconds. Remove the PCB and remove the photo template.

4. Develop and harden solder-resist mask

Prepare the developing bath with developing powder and hot water.

Use a brush to release the unexposed solder resist in the developing bath.

The solder resists, then hardened and cleaned in a convection oven for 30 minutes. A powder pH-conditioner then neutralizes all chemical components for eco-friendly disposal.

This list may change as integrated circuit chips become more common in the hobby market.

I am already the mainstay component on most professional boards and in any device that needs computational functionality.

3. Choosing PCB Components

The best PCB designs use the best components for the job. There is no other way to do it. With the right PCB components, your circuit will provide fewer avenues for failure and cost the least to make.

If you do not choose the components wisely, you may run into problems later on that can significantly increase your project’s costs, especially if some of the components are rare and expensive.  

You can do a few things to ensure you only use the right components for your project. You are just following these rules.

1. Plan out your project with schematic diagrams.

Before you touch any real components, you should complete your project virtually. An excellent schematic diagram will show you what components and where you need them.

You can then use the schematic to create a Bill of Material for the components with appropriate dimensions and quantities.

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Figure 2: Standard schematic symbols for common production film work you require to manufacture PCBs. In the case of PCBA components

2. Select the right mounting.

Surface mounting costs the least, but it is generally only viable with small machine-assembled components.

If you mount your components by hand, you want to use a through-hole mounting system that allows for more significant components.

3. Space components concerning their requirements.

Each component has a clearance requirement. You need to ensure enough space around them to dissipate heat and prevent accidental short circuits.

Please note that power parts have the highest clearance requirements, and their heat can physically warp the underlying PCB.

4. PCB components have soldering requirements.

You want to know if you can solder things by hand or through a reflow oven.

That is because you want significant, through-hole components for your significant functions if you hand-solder your board, only moving to lighter components for the smaller areas and functions.

By following this short list of rules, you will streamline your projects with only the necessary components.

This will save you money and free up more time that you can use on other projects or test your project before you release it.

4. Electronic Parts & General Supplies

Having an excellent PCB plan is nothing without the components to build them. However, recent changes in the industry may make it difficult to find the parts.

For most hobbyists, you must buy your parts Custom PCB circuit board may, therefore, be a tall order. This article will walk you through five basic ways to land the best PCB board online or scavenge the parts from other devices.

Each method has its pros and cons, and you will have to expect to take a significant amount of time to gather everything you need before you can begin.

Gathering supplies is the most extended aspect of PCB building, and there is no real way to make it go faster.

Generally, you want a list of go-to suppliers that you know will have most, if not all, of the parts you need. While you can find great lists online, only you can make one.

That is because you may have a favorite local shop that can get you the needed parts instead of waiting for them to ship through the mail.

Either way, once completed, your electronics parts shop list will be a quick reference to get your projects going, saving you time and money for more critical tasks.

If you do not have a parts supplier near you or cannot find the parts online, you will get them from pre-existing boards and devices.

Thus, you need to know how to identify the parts of these old donor boards so you can recycle anything that still works.

While newer boards should use the above standards, older boards may use more restrictive means of identifying their components.

Fortunately, you should be able to find the schematics of those older bards online.

4.1 Television Circuit Board Components Identification

Old televisions are a public source of donor electronics parts. These devices are usually obsolete to serve as televisions and get tossed in the trash.

That also means that you can often get these boards for free in many cases.

You want to ensure their components work before reusing them, but they are comfortable and fun options when you need PCB parts for your project.

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Generally, you should only worry about the electrolytic capacitors and resisters. These components tend to age when heated, which can permanently change their values.

The rest of the components should be okay, though you want to ensure nothing is burned out. You must be careful when removing them as you could damage their leads, rendering them useless.

For the most part, old television components have what they are printed on them. Plus, common components still look like they did in these machines as well. The only real difference on the old TV boards is the rectangular resistors.

Some odd TV components you may find include:

       • AM IF resonator. Usually a small orange box, this is an oscillator crystal. They usually oscillate at 455 kHz, but 500 or 560 kHz resonators can be found.

       • Tantalum electrolytic capacitors. They are small and blue.

       • Ceramic resonators. These three-pin components act as filters for audio signals.

       • High-voltage resistors. These are large white boxes with information printed on them.

       • Delay line. These large components delay signals through a circuit.

4.2 Mobile Circuit Board Components

Mobile circuit boards are generally more comfortable to use than television boards.

For one, nearly all of them use modern electronic component identification standards.

So, you should already have the skills necessary to find what you need.

Secondly, old mobile devices are more accessible and cheaper to find.

You may have a few old devices yourself, as most people tend to upgrade their mobile technology regularly.

Still, it is always a good idea to know what each part does before you crack open a vintage iPhone.

Your average phone has a surprisingly large circuitry inside, and most of it is optimized for performance.

You can find both analog and digital electronics sitting and working next to each other.

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Mobile Networking

While multi-board devices do exist, most mobile electronics are on a single PCB. However, this PCB is divided into two sections: network and power.

Each section has its own needs and functions, so you should keep them in mind when hunting for parts.

The Network half contains all the radio frequency elements and is the crucial circuitry that makes the mobile device work.

At the top, the antenna and antenna point sit apart from the rest of the circuit.

Below the antenna point, you will find the transmitter and receiver circuits.

Notable components in this area are:

       • Antenna switch. The switch has metallic and non-metal parts with 16 points or legs below the antenna point. It is white in GSM-network devices but golden in CDMA devices.

Please note that some devices merge their switch into their PFO.

       • Power frequency oscillator (PFO). Also called the power amplifier (PA) and bandpass filter, the PFO is a crystal oscillator that manages the device’s wireless signal.

It is either located next to or inside the antenna switch.

       • The 26 MHz Crystal Oscillator, also called the network crystal, generates transmission signals. It is found in a metallic box near the PFO.

       • Network IC. The network IC provides signal transmission logic. You will usually find it below the antenna switch and PFO, but some devices merge this IC into the CPU.

       • RX and TX Filters. These black boxes filter and regulate the incoming and outgoing signals, respectively.  

       • Voltage-controlled Oscillator (VCO). This IC converts the signal between analog and digital.  

4.3 The Power Section

The power section is the heart of the mobile device, containing all of its computing components.

       • Power IC. Encircled by several brown-colored capacitors, the power IC manages the battery to power the entire device. Some devices may have two of these circuits.

       • Central Processing Unit (CPU). The CPU is the largest IC on the PCB.

       • Flash IC. Located next to the CPU, the Flach IC is the ROM that provides the preconfigured software.

       • ROM and RAM. The read-only and random-access memory ICs are located next to the CPU.

       • Charging IC: The charging IC is located near Resister 22 and regulates battery recharging.

       • Audio IC. Located next to the Power IC, this is the mobile device’s sound chip.

       • Real-Time Clock (RTC): Located next to the Power IC, this silicon oscillator is the PCB’s clock.

       • Logic IC. The logic IC operates the ringer, vibrator, and LEDs. There is no universal location for it, though.

5. Understanding The Electronic Components Market

Understanding the electronic components market is necessary for components distributors, manufacturers of electronic equipment, and many others. In times of boom, components are more laborious to source, prices rise, and lead times significantly increase.

In times of recession, prices fall, and availability increases, especially for semiconductors. Planning can enable manufacturers to keep production lines running while also keeping costs down.

5.1 Significant Factors For The Tendency Of Electronic Component

Many known factors affect the overall market. One factor is analyzing existing growth trends globally and for different countries.

Another is the new and growing electronics industry sectors. Automotive and the new Internet of Things sectors are expected to grow significantly, driving overall growth.

Sectors like mobile and fixed telecommunications and computer devices of all forms. Moreover, many others are well-established and likely to grow less.

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5.2 However, Many Unknowns Could Affect The Economic Conditions That Govern The Overall Global Economy.

The output of the electronics industry is multiplying.

Devices based on acoustoelectronics and magnetoelectronics are also increasing.

Rapid expansion has distinguished the production of such equipment as microcomputers, color picture tubes, and electronic calculators (including programmable calculators).

As well as video recorders, electronic watches, and high-quality stereo systems.

Many of these innovations, such as the transistor, originated in research, which needed increasingly sophisticated electronic devices for modern high-tech warfare.

The consumer electronics industry is a primary end-user market for electronic components, which explains the recent spurt in demand for electronic devices.

It is lending significant traction to the global electronic components market, particularly in developed markets.

Electronic device manufacturers are increasing their production capacity to meet the growing demand for electronic devices, such as Wireless Communication Equipment.

Data Network Infrastructure needs multilayer PCBs. Industrial expansion in emerging markets and the Electronic medical industry.

Also, increases the market for electronic components.

The electronics industry will become more competitive, and the costs and markets for electronics components will significantly increase.

Therefore, more innovative technology is required to make the right component selection.


A fully functioning circuit board contains several components that work together to achieve a specific function. Knowing how to identify these components will help you plan out and build your next project.

Beyond that, you need to know their limits, and not all components are needed in every project.

Through this process, you will have a PCB project that you can complete under budget in a reasonable amount of time.

If you need components, you can scavenge them from old PCBs, such as those found in old televisions and mobile devices, or buy them from a reputable supplier.

Although buying the parts may cost more, it is the only way to ensure that all your components work before you solder them onto your board.

If you need assistance in finding your components, you can go circuit board shopping. Various things might get you confused.

Whether you are going for a single-sided PCB, a double-sided PCB, or any other type of PCB, you can contact us for advice.

We provide a one-stop turnkey PCBA service, and we are here to help you purchase all your PCBA supplies.

All of our assembly components come from reputable Digikey and Mouser companies.

Therefore, you can rest assured that our components have the best quality and price on the market.

Extended Reading

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Emma Lu
Our professional engineering support saves our customers a lot of trouble and loss. >>>>>> After you place the order, our engineer will conduct technical reviews to make sure the parts can be mounted well/correctly on the boards. We will check if the component packages match well with the Gerber footprints, if the part numbers you provided match well with the descriptions, and if the polarity is clearly marked. >>>>> When your design is ready, please send your Gerber and BOM so we can quote and start!