All electronic products across the globe use one form of the printed circuit board or another. Therefore, the significance of PCBs and their manufacture cannot get lost to enthusiasts, designers, and everyday ordinary electronic product users. However, PCBs without the attached electronic components reduce them to bare boards, and therefore their meaningfulness also reduces significantly. The standard electronic components on PCB provide it with the defined functionality required in its specific application area.
Common Electronic Components on PCB
Circuit board components come in various forms, and alongside the type of PCB, define the overall application of the circuit board. Therefore, it becomes prudent to factor in the correct electronic components during the design phase to ensure a seamless fabrication and assembly process. Further, it also guarantees the proper functioning of the PCB in their respective area of deployment.
Picking a suitable PCB part can prove difficult as numerous standardized off-the-shelf components exist. While some of the standardized parts can prove alluring due to how fast, convenient, and simple buying process proves, other vital details proprietary to your PCB project may lack. It, therefore, means that the process will become more arduous and lengthier in the long run. But in understanding the electronic components needed for your printed circuit board assembly, the process becomes simpler.
Understanding a PCB Component
Printed circuit boards come as complicated electronic elements necessary in the overall functionality of an electrical or electronic device and equipment. PCBs have components, which imply the electrical part that proves instrumental in their development or manufacture. Circuit board parts or components encompass a wide range and include capacitors, diodes, resistors, fuses, etc. Printed circuit boards rely on every electronic component playing its role properly to ensure the functional efficiency of the board. If one component malfunctions or fails, then it affects other areas and components of the circuit board, ultimately impacting the overall functionality of the circuit board.
The universality of printed circuit boards when it comes to PCB parts proves unparalleled. Therefore, the ingredients necessary for the whole design process matter, especially for an engineer or designer. It becomes therefore crucial to consider different component aspects when picking them for your PCB.
Aspects to Consider in Component Identification
The type of PCB
Determining the type of printed circuit board needed for the specific project requirements is a critical aspect. Diverse electronic circuit boards exist out there, including rigid, flex, and rigid-flex printed circuit boards. Try and determine whether your project will get served best with either of the three types of PCB before picking the accompanying components.
Identify the “Bolt and Nut” Circuit Components
It is always critical for you to fasten the printed circuit board as a designer or engineer. However, fastening implies using bolts and nuts that you must also factor in and pick. Bolts have different sizes for their length, though nuts mostly come standardized in terms of their sizes. After determining the spots in which you will fasten the PCB, you can pick a suitable bolt fastener or nut fastener.
The Fuse, Battery, transistor, and Diode of the PCB
Universally, components such as diodes, transistors, showers, and fuses prove instrumental elements on the printed circuit board. The battery serves as the power or energy source or tower to power the whole rigid flex PCB. On the other hand, the transistor becomes instrumental in amplifying the charge while a diode permits the unidirectional current flow by blocking the flow in the opposite direction. Fuses break the current flow, especially when it proves excessive and thus protects the entire circuit.
Processors
Most printed circuit boards need a processor as they play a pivotal role in providing a suitable output upon receipt of an input. Therefore, based on the components on bare PCB, you might have to incorporate one or more processors. Modern printed circuit boards incorporate numerous processing cores, which work in tandem when it comes to information processing or processing of instructions.
Connectors on Small PCBs (Primarily on Motherboards)
Printed circuit boards require connectors, and these often come as small devices that can interrupt circuitry or the circuit paths quickly and easily. It comes in different sizes, shapes, complexities, and quality levels. However, the most predominant connector entails the two-piece board-to-board and one-piece card edges. For small printed circuit boards, the one-piece card edge proves the ideal connector.
Other Circuit Board Chips
Plenty of electronic circuit board parts or components go into the PCB manufacturing process in the form of chips. Chips become instrumental for PCBs for diverse reasons and thus get incorporated besides other electronic components like diodes, transistors, and fuses. Chips can contain components like LEDs, copper, potentiometers, capacitors, etc.
RAM Connection Position
The device’s memory proves a vital aspect of the PCB. RAM denotes random access memory and allows for the direct access of any memory cell once you have established the intersection of the cell’s row and column. The position of the RAM connection spot within an electronic circuit board proved vital. It influences the functional efficiency of the PCB. RAM should get placed near the central processing unit socket.
Commonly Deployed Components on PCB
Components on PCB tend to function in complementarity to form a comprehensive system capable of powering our devices. It can compare to the arrangement of a city with the various and instrumental pieces necessary in its proper functioning. So what kinds of electronic circuit board parts exist today?
Resistors
It represents a popular electronic component widely used in printed circuit boards. Resistors come simple and operate to provide current resistance through the dissipation of electric power in the form of heat. It can come in diverse types, each having a separate range of materials. However, the typical resistor almost everyone knows entails the axial resistor that possesses leads on either long end with different color inscriptions (rings) on the body. The rings function as codes in indicating the resistance value. However, always research or ask RayMing PCB and Assembly customer care for more informative details if you get stuck deciphering the implications of the color rings.
Features
- Temperature coefficient of resistance that comes reliant on the resistor construction and resistive material
- Temperature dependence when it comes to electrical resistivity gets determined by the material.
- Power rating, which stipulates or indicates the component’s maximum dissipation. Dissipation rating gets specified at room temp besides decreasing with high temperatures.
- Based on the type of resistor, it may become prudent to have properties of low noise. It is dependent on temperature, resistance, and bandwidth.
- Frequency dependence. The aspect of parasitic capacitance and inductance becomes increasingly pivotal in higher frequencies whenever the parasitic effects prove negligible in instances where the resistor has decent high-frequency attributes and operates within the acceptable range of operating frequency.
- Wire insulation mostly comes in enamel insulation (potentially wounded with fiber, silk, cotton, etc.)
- Protection from environmental influence where the expansion coefficients need to prove uniform in cases where the resistor body gets insulated with enamel paint
- Lasting stability, which indicates the higher limit of the tolerable resistance value change
- The maximum permitted voltage, etc.
Capacitors
It is vital component that proves popular with almost any type of circuit board. The common components (only behind resistors) function as temporary hold areas for electric charge. Capacitors then release stored charge whenever other areas of the electronic circuit need the extra power. It operates by amassing opposite charges, primarily on two conducting layers that sandwich a non-dielectric nonconductive material. Capacitors get categorized based on the conductor material. Therefore, finding plenty of capacitor types with varied features from high capacitance electrolytic, different polymers, to stable ceramic disc capacitors. Additionally, some capacitors have similar appearances to those of axial resistors. However, the classical one comes in a radial style, complete with dual lead protrusions.
Features
- Nominal capacitance can either come as fixed or varied capacitance based on the capacitor type.
- Working voltage denotes the maximum voltage any capacitor can constantly receive without failure or incidences of damage.
- Tolerance is another key attribute that can also vary based on the capacitor type. It ranges from as low as 1% tolerance to about 80% tolerance in some instances.
- Leakage current. The dielectric material that forms part of the capacitor allows leakages (small percentages), influencing the insulation resistance.
- The working temperature also influences the ability of the capacitor to store charge or electrical energy.
- Temperature coefficient, which measures the capacitance change arising from a ranging temperature
- Polarization is another key feature of capacitors and infers to the plates’ charge within a capacitor. In most instances and capacitors, it will have both a negative and a positive terminal. However, matching the positive voltage to the positive terminal, besides the negative voltage to the negative terminal when applying voltage, becomes critical. Inaccurate polarization leads to severe damage.
- ESR or equivalence denotes the overall resistance for each part or segment of the capacitor that resists.
Inductors
It represents the last member within the linear passive parts or components family. The other includes the capacitors and the resistors. Inductors store energy, similar to capacitors though instead of stockpiling it as electrostatic energy, it accomplishes it in the form of the magnetic field. One of the simplest inductors comes in the form of a wire coil. However, the higher the coiling or windings, the greater the magnetic field the inductor possesses.
In most cases, you will find inductors as wires coiled around magnets with diverse shapes. It amplifies the magnetic field and, as a consequence, the energy stored. The common application of inductors entails deployment in blocking specific signals. For instance, it can block signal interference in radios (devices and equipment) or get deployed alongside capacitors in manipulating AC signals, especially in switched-mode power supplies.
Features
- It is a time constant because it stores energy in the form of a magnetic field. Therefore, the stored energy maintains a continuous current (oppose changes in current), unlike a capacitor that maintains a constant voltage.
- Current and voltage. The voltage produced in an inductor proves dependent on how quickly the current flow decreases.
- Current flows to create a magnetic field, whereas any change in this field generates or forms an opposing current.
- It can allow the flow of DC at high frequencies and not AC at similar frequencies.
Potentiometers
It comes as a variable resistor form and proves common in its linear and rotary types. Varying of the resistance becomes possible through the rotation of the potentiometer’s knob. It accomplishes this by moving the slider contact over the semi-circular resistor. An excellent example includes the volume regulator in radio systems, where it regulates the sound by controlling the total current channeled to the amplifier. A linear potentiometer operates similarly, though the resistance varies by shifting the slider contact along with the resistor. It proves excellent in fine-tuning whenever necessary.
Features
- It works on a comparative method compared to the deflection pointer one, which makes it reliable to establish unknown voltages.
- It functions without any need for current as it operates away from the resistance source.
- A potentiometer measures the balance or null point, which often negates the need for power when measuring.
Transformers
The transmission of electrical energy from a circuit board to the next serves as its primary function. However, the transfer happens with a decrease or increase in the voltage. Like an inductor, a transformer comprises a soft iron core or base with coils (at least two coils) wound around it. It comes in two types – a primary coil and a secondary coil. For instance, the prominent step-down industrial transformers located on telegraph poles represent a typical example. It converts or transforms hundreds of thousands of volts to a few hundred required for household needs.
Features
- The output and input power possess similar frequencies
- Every type of transformer functions on the principle of induction (electromagnetic induction)
- The secondary and primary coil proves unconnected
- The loss featured in a transformer proves way less compared to other devices or components.
Diodes
It is an electronic component, which only allows the unidirectional flow of current – from the terminal denoted anode to the cathode. It functions by possessing zero resistance in one specific current flow direction with high resistance in the other direction. The features prove a key one is also blocking the flow of current into wrong or unintended directions, thereby averting danger or damage. One of the most prevalent diodes encompasses the LED (light-emitting diode), which emit light. Getting the orientation of such a diode becomes key in ensuring the LED functions properly.
Features
- Forward voltage drop, which allows for a forward bias of the voltage, normally about 7 volts
- Reverse voltage drop necessitates the widening of the depletion layer upon applying the reverse bias, which leads to the applied voltages getting felt.
- Reverse breakdown voltage features reverse voltage drop that reverses the flow of current and, in most instances, destroys the diode.
Transistors
It has a widespread reputation as a fundamental building block for contemporary electronics. It is possible to find billions of transistors on one chip. Transistors prove similar to amplifies though ones containing electronic switches. It comes in diverse types, though the most popular proves the bipolar transistor. It (transistors) can further get categorized into PNP and NPN versions. Bipolar transistors contain three pins in the collector, the base, and the emitter.
NPN transistor types feature the flow of current from the base to the emitter. It then turns on another electronic circuit by causing the current flow from the collector to the emitter. For PNP transistors, the flow of the directions gets reversed. Another type of transistor entails the FETs or field-effect transistor that utilizes the electric field in activating the other electronic circuit.
Transistors are instrumental in detecting, rectifying, switching, amplifying, modulating signals, besides stabilizing voltages. It controls the output current though this depends on the voltage input.
Features
- Input characteristics that describe input current changes. The input voltage values vary and keep the output voltage consistent or constant.
- Output characteristics plot the output current vis-à-vis the output voltage with consistent input-output.
- Current transfer features demonstrate the output current variation in line with the current inputted. It keeps the output voltage consistent or constant.
SCR or Silicon-Controlled Rectifier
It also gets referred to as thyristors and comes similar to diodes and transistors. Essentially, it implies two transistors functioning together. The SCR has three leads (cathode, anode, and a gate) and contains four silicon layers instead of three. It serves as a switch and not as an amplifier. The other difference entails the need for only one pulse to activate the switch while current requirements are applied consistently, especially for an individual transistor. An SCR also proves ideal for switching large amounts of charge or power.
Features
Forward Characteristics
- Upon the increased supply of voltage, the CSR begins conducting and results in a break-over voltage.
- Upon the proper current flow on the gate, the SCR potentially closes at a smaller voltage supply.
Reverse Characteristics
- The anode current holds a small leakage current at first. Beyond a specific reverse voltage, the SCR begins to conduct massively, which leads to reverse breakdown voltage.
Integrated Circuits
It represents circuits and electronic components all collapsed onto a wafer created of semiconductor material. The vast number of electronic components capable of fitting into a single chip led to the initial calculator. However, the situation has progressively evolved from more complex devices such as smartphones, computers to supercomputers. IC or integrated circuits function as the brain of the wider circuit. It gets encased within a plastic casing that can vary in shape and size besides visible contacts, significantly when the leads protrude from the contact pads or body under the BGA chip.
Features
- It is developed from semiconductor materials that have an outstanding balance between insulation and conduction.
- Multiple and tiny components are integrated using a set of aluminum and gold wires on a block (flat) of ceramic or plastic.
- However, dimensions vary from one sq. mm to over 200 sq. mm. the plastic casing or package proves a few factors larger.
- Integration of discrete devices, especially when it comes to functionality to allows for the tiny packaging.
Crystal Oscillators
A crystal oscillator is instrumental in clocking circuits, especially those that need stable and precise timing elements. It produces a periodic signal by causing a physical oscillation of a crystal material. Every crystal oscillator by design has to vibrate at specific frequencies. It also proves a stable, affordable, and more reliable option possessing a small form factor than other timing methods. As a result, they get deployed as exact microcontroller timers or otherwise inferred as quartz wristwatches.
Features
- A load capacitance of 18pF
- A frequency tolerance range of plus/minus 30ppm
- A maximum of 40 ohms resonance resistance
- A drive level of less than a hundred microwatts
- An operating temperature range of -20 to 70 degrees Celsius
Relays and Switches
It mostly gets overlooked though it plays a fundamental role in the printed circuit board. The switch controls the flow of current within the circuit by switching between closed and open circuits. It varies based on the physical appearance, rotary, lever, push-button, key switches, lever, etc. On the other hand, a relay comes as an electromagnetic switch that gets operated through a solenoid. It functions as a temporary magnet whenever current flows through. It thus serves as a witch besides amplifying small amounts of current.
Features
- The relay can come with contacts or without contacts, with each having distinctive characteristics.
- The switch operates in the second layer and entails an intelligent network device capable of getting regarded as a multiport network bridge.
- A switch also deploys MAC addresses when it comes to sending data packets to the targeted destination ports.
Sensors
It is instrumental in detecting environmental changes besides generating a signal that corresponds to that specific change. Such signals get sent to the relevant circuit electronic components. It converts energy from the available physical forms into electrical energy, thus a transducer form.
Final Thoughts
Electronic components are vital for the operational soundness of a printed circuit board. The arrangement of the components on PCB also proves critical in ensuring that components work together. But before understanding the arrangement aspects of the PCB components, comprehend the various components detailed in the article.
