In our last article, we wrote about PCBA’s definition and its process steps. Next, we will talk about the electronic components on printed circuit board.
What are the electronic components on the PCB board?
The electronic components on PCB assembly are not just additional circuitry, they are the critical parts of any electronic product and each part has a specific function in the system’s circuitry. As the electronic devices advances, there came out a number of different types of electronic components available in the market. These are extending resistors, capacitors, gossip inductors, communique transformers, and gossip crystal diodes, crystal transistors, Integrated circuits, sensors etc.
1. Resistance
Electrical components that hinder current flow are one of the most fundamental components in circuits. Used to restrict the flow of current, regulate the power and damping of circuits. With less resistance there are more electrons which can flow and vice versa is the case with more resistance. Every Explanation of Electronics Resistor stresses on their resistance value and power because those two parameters define the activity of the resistor in any given circuitry and in most cases, a wrong selection of a resistor could cause problems with stability of the circuit.
Different types of resistors include fixed resistors, rotary resistors, potentiometers, etc. Resistors are widely used in circuits, such as in filters and power regulation.
2. Capacitor
Capacitors are a common type of electronic component that primarily function to store electrical charge. Can quickly charge and discharge, filter out interference signals in the circuit. The amount of electrical charge stored in relation to some potential difference is called capacitance; this is symbol C and the SI unit is Farad (F). Selection of the right type of capacitors is essential for the enhancement of stability and performance of sound reproduction circuits. In the PCB capacitors are used for decoupling, filtering, voltage stabilization, reducing noise, etc. The capacitors are also classified into several types, the most popular being ceramic capacitors and aluminum electrolytic capacitors.
3. Inductance
Inductors are electronic components that can store magnetic field energy. Its function on the PCB board is to limit current, transform voltage, stabilize voltage, etc. The types of inductors include iron core inductors, air core inductors, magnetic inductors, etc. Inductance is used to suppress sudden changes in current and act as a filter. It is usually combined with capacitance to form a filter to eliminate interference in AC signals.
Inductance of an ideal inductor is a property of a closed circuit and a physical quantity. When a current passes through the coil, a magnetic field induction is formed in the coil, and the induced magnetic field generates an induced current to resist the current passing through the coil. The interaction between this current and the coil is called electrical reactance, also known as inductance, with the unit being "Henry (H)".
4. Transistor
Transistors are also electronic components made of semiconductor materials, and their applications are very extensive. They can be used in various circuits, such as amplification circuits, switch circuits, signal processing circuits, etc. On PCBs, transistors are mainly used in the design and manufacturing of logic gate circuits.
Crystal diode: abbreviated as diode, it can achieve functions such as half wave rectification, full wave rectification, current limiting, and voltage transformation. On PCB boards, diodes are often used for power management and optoelectronic devices. It is an electronic component that only transmits current in one direction. It is a device with two terminals connected by one part number, which has the property of allowing current to flow or not flow in the direction of the applied voltage. The main feature of these devices is their nonlinear current voltage characteristics.
Crystal transistor: The full name should be semiconductor transistor, also known as bipolar transistor or triode. It is a semiconductor device that controls current and amplifies weak signals into larger amplitude electrical signals. It is also used as a contactless switch. A transistor is made by fabricating two PN junctions that are very close to each other on a semiconductor substrate. The two PN junctions divide the positive block semiconductor into three parts, with the middle part being the base region and the two sides being the emitter and collector regions. There are two types of arrangements: PNP and NPN.
Field effect transistor: abbreviated as field-effect transistor. Conducted by majority carriers, also known as unipolar transistors. It belongs to voltage controlled semiconductor devices. It has the advantages of high input resistance (108-109 Ω), low noise, low power consumption, large dynamic range, easy integration, no secondary breakdown phenomenon, and wide safe working area, and has become a strong competitor to bipolar transistors and power transistors.
5. Sensors
A sensor is an electronic component that detects, measures, and controls certain changes. Sensors can sense physical quantities or states in the environment and convert them into electrical signals for output. They are commonly used to detect parameters such as temperature, humidity, light, pressure, etc., providing data support for intelligent control of electronic devices. They are widely used on PCB boards.
Classified by purpose: pressure sensitive and force sensitive sensors, position sensors, liquid level sensors, energy consumption sensors, speed sensors, acceleration sensors, radiation sensors, thermal sensors.
Classified by principle: vibration sensors, humidity sensors, magnetic sensors, gas sensors, vacuum sensors, biosensors, etc.
Classified by output signal: analog sensor, digital sensor, pseudodigital sensor, switch sensor.
6. Transformer (mainly used in rigid PCB)
Transformer is a device that uses the principle of electromagnetic induction to change AC voltage. Its main components are primary coil, secondary coil, and iron core (magnetic core).
Transformers are used for AC voltage conversion, current conversion, power transfer, impedance conversion, and buffer isolation, and are one of the essential components in PCBA machines.
7. Integrated Circuit
Integrated circuit is a type of chip that integrates multiple components including transistors, other active components, capacitors, resistors, etc. Implementing specific functions such as a microprocessor, etc., and memory chips, etc. can as well contribute in reducing the physical size and weight of circuit boards. Owing to the rapid growth of Eastern Asian countries, the number of different integrated circuits on the market is huge, for example: linear ICs, digital ICs, and mixed ICs.
8. Connector
Connector is one of the parts which are found on a PCB circuit board, whereby it is mainly used for interconnection of electrical components and other devices or printed circuit board. In this case there are several of them such as plug connectors, plug in connectors, and pin connectors etc. When using them one should select depending upon his or her interests.
9. Processor
The processor is one of the most essential parts on the PCB with basic duties being processing machine instructions and data storage. Such include those classified as embedded processors, micro processor, chipsets and others used in embedded systems and computer applications.
10. Crystal oscillator
Body oscillator is an electronic device used to generate stable frequency signals, generally used for clock signal generation, and widely used in electronic devices such as computer motherboards, communication equipment, televisions, etc. The core component of a crystal oscillator is a small crystal called a "crystal", typically made of quartz material.
11. Power module
The power module is used in circuit board to provide stable power and ensure the normal operation of the circuit board and its components. They meet specific voltage and current requirements through different types such as linear, power switch, DC-DC converter, etc., while considering design points such as efficiency, stability, and heat dissipation.
12. Antenna
Integrated antenna or printed antenna are more frequently included in wireless communication device technologies. Antennas are responsible for the reception and transmission of radio frequencies and thus facilitate a wireless link between all the installed devices and the outside world.
The selection and application of these electronic components directly affect the performance and stability of the circuit, so careful selection and testing are required in the PCBA design and production process to ensure the reliability and performance of electronic devices.
What are the characteristics of components used on flex PCBs?
Components used on flexible printed circuit boards have some special characteristics that enable them to adapt to the unique requirements and application scenarios of flex PCBs. The following are the main characteristics of these components:
1. Lightweight and miniaturized
Components are typically designed to be very lightweight and compact to meet the lightweight and compact design requirements of flexible PCBs. This is particularly important for portable and wearable devices.
2. Low profile
The height of the components is relatively low to reduce the impact on the bending radius of the flex PCB and avoid damage to the components or circuit board itself during bending or folding.
3. High reliability
Components need to have high mechanical reliability and be able to withstand repeated bending, stretching, and folding of flex PCBs during use without failure.
4. Thermal management
Good thermal management characteristics, due to the fact that flexible PCB materials usually have lower thermal conductivity than rigid PCBs, components require more efficient heat dissipation design or are designed with low power consumption to reduce heat generation.
5. Flexible installation
Special packaging and installation techniques: Some components are installed using flexible packaging or adhesive instead of traditional soldering methods to better adapt to PCB bending.
6. Environmental resistance
Environmental stress resistance: Components often need to withstand a wider range of environmental conditions, including temperature changes, humidity, vibration, etc., as flexible circuit boards are typically used in dynamic and harsh environments.
7. Low weight
Components and connectors are designed to be as lightweight as possible to maintain the overall lightness of flexible PCBs, especially in aerospace, automotive electronics, and wearable devices where weight is a key factor.
8. Consistency of electrical performance
Good electrical performance consistency: Although flexible PCBs may deform during use, components still need to maintain stable electrical performance to ensure the reliability of circuit functionality.
9. Specialized connector
Customized or specialized connectors: Due to the unique physical characteristics of flexible PCBs, customized connectors are often required to ensure reliable electrical connections while balancing flexibility and ease of disassembly.
10. Surface Mount Technology
Widely used SMT technology: Due to the structure of flex PCB, most components adopt SMT to achieve compact layout and high-density assembly.
These features enable components used for flex PCBs to not only meet the functional requirements of electronic devices, but also maintain stable operation under harsh physical and environmental conditions.
What is the difference between FPCBA and PCBA?
The PCBA we usually understand refers to Rigid PCB Assembly, while FPCBA is flex PCB Assembly. Although components installed on traditional rigid PCBs and components installed on flexible PCBs may have similar functions, there are some key differences in the design, installation, and performance requirements of components due to the different physical characteristics and application environments of the two circuit boards.
1. Mechanical stress and durability
Rigid PCBs typically do not bend, so components do not need to consider flexibility or durability issues. They can be fixed using standard welding methods, and the installation of components is usually focused on stability.
The components on flex PCB need to be able to withstand repeated bending, folding, or stretching of the circuit board. This requires components to have higher mechanical durability, and stress concentration issues need to be considered during installation. Flexible packaging or specific installation techniques may be used to reduce stress.
2. Packaging form
There are various forms of component packaging on traditional PCBs, including larger volume through-hole components (THT) and surface mount components (SMT). Because rigid PCBs typically have more space and better support, component packaging can be unrestricted by space and shape.
flex PCBs are typically used for space limited and curved applications, so most components are SMT, and packaging is often very miniaturized and flattened to reduce the overall thickness and weight of the circuit board.
3. Thermal management
Rigid PCBs typically have good thermal conductivity and a large heat dissipation area. Therefore, thermal management of components can rely on PCB heat dissipation, and even heat sinks or fans can be installed.
The heat dissipation design of components on flex PCB needs to be more cautious. Usually, components are designed with low power consumption to reduce heat generation or adopt more efficient heat dissipation solutions.
4. Installation method
Components on traditional PCBs can be installed using standard soldering processes, with stable mechanical connections and no need to specifically consider stress issues. Both through-hole components and surface mount components are common.
The installation process of components on flexible circuit board needs to consider the bending characteristics of the board, and special soldering processes or adhesives may be used to fix the components to avoid damage caused by stress. Special consideration needs to be given to the design of joints and connectors to ensure reliability.
5. Environmental adaptability
Components on traditional PCBs are typically designed to operate in a fixed physical environment, taking into account conventional factors such as temperature and humidity.
Components on flex PCBs need to adapt to dynamic and potentially more harsh environmental conditions, such as sustained mechanical stress, extreme temperature fluctuations, etc., so components often have higher environmental tolerance.
6. Connection method
Components on traditional PCBs typically use larger connectors, which are suitable for rigid structures and have high insertion and extraction forces.
The components on flex printed circuit board use specially designed small, low insertion force connectors to ensure reliable connection during bending or movement.
7. Cost
Traditional PCB components: usually relatively inexpensive, with mature manufacturing processes, a wide variety of component types, and a wide supply chain.
flex PCB components are usually expensive, and due to the need to consider special performance requirements, some components may require customization or special procurement.
These differences result in the need to use components that are suitable for their characteristics when designing and manufacturing flexible circuit boards to ensure the reliability and performance of the overall system.
Conclusion
Now you should have a good understanding of what flex PCB assembly components are. Once you have a flex PCB substrate, you can organize various components on the board, such as transistors, transformers, ICs.
The two technologies of PCBA are SMT and through-hole. You must be careful to install these components correctly. At Flex Plus, you are sure to get the most accurate and precise FPCBA on time at a competitive price.
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