PCBA processing can not be separated from various electronic components, such as resistors, capacitors, inductors, crystal diodes, crystal triodes and other basic components of electronic circuits. The performance and quality of electronic components have a great impact on the quality of PCBA finished products. What are the common PCBA electronic components?
Resistors are electronic components with resistance characteristics, and are one of the most widely used components in PCBA, usually called resistors. Resistors are divided into fixed resistors and variable resistors (potentiometers), which play the role of voltage division, shunt and current limiting in the circuit.
The resistor whose resistance value can change, that is, the resistor that can be continuously adjusted within a specified range, is called a potentiometer. The potentiometer is composed of a housing, a sliding end, a rotating shaft, a ring resistor body and three leading out ends.
Capacitor is one of the basic components in PCBA processing. It is a kind of component that stores electric energy. It plays the role of coupling, filtering, isolating DC and tuning in electronic circuits.
Inductance coil is called inductance for short, which has the function of storing magnetic energy. Inductors are represented by the letter symbol L. Inductive coil is usually composed of skeleton, winding, shielding cover, magnetic core, etc.
The transformer is composed of an iron core (or magnetic core) and a coil. The coil has two or more windings. The winding connected to the power supply is called the primary coil, and the other windings are called the secondary coil.
A transformer is a device that transforms voltage, current and impedance. When the primary coil is filled with AC current, AC magnetic flux will be generated in the iron core (or magnetic core) to induce voltage (or current) in the secondary coil. The transformer is mainly used for AC voltage conversion, current conversion, power transfer, impedance conversion, buffer isolation, etc. It is one of the indispensable important components in the whole PCBA.
Crystal diode (semiconductor diode, hereinafter referred to as diode) is made of a PN junction, electrode lead and external sealed shell, which has unidirectional conductivity.
Crystal triode (hereinafter referred to as triode) is the core device of signal amplification and processing, which is widely used in PCBA.
Field effect transistor
Field effect transistor (FET) is also a semiconductor device with PN junction. Different from triode, it does not use the conductive characteristics of PN junction, but its insulation characteristics.
Silicon controlled rectifier
Silicon controlled rectifier, the abbreviation of silicon controlled rectifier, is a high-power semiconductor device with three PN junctions and four layer structure, also known as thyristor. With the characteristics of small size, relatively simple structure and strong function, it is one of the commonly used semiconductor devices.
Integrated circuit (IC) is to use semiconductor technology or thick and thin film technology (or a combination of these technologies) to make the active devices (transistors, FETs, etc.) and passive components (resistors, capacitors, etc.) of the circuit and their wiring on the semiconductor substrate or insulating substrate, form a circuit with specific functions, and package them in the shell. Compared with discrete component circuits, integrated circuits have the advantages of small size, light weight, low power consumption, low cost, high reliability and stable performance, and are widely used in PCBA electronic products.
The device used to complete the mutual conversion between electrical signal and sound signal in the circuit is called electroacoustic device. It has a wide variety of speakers, microphones, earphones (or earplugs), transmitters, receivers and so on.
Switches, relays and various connectors
Switches are used in electronic equipment to cut off, connect or transfer circuits.
Relay is a kind of automatic control device that will change the output by leaps when the input (electricity, magnetism, sound, light, heat) reaches a certain value.
Surface mounted components
Surface mounted components (SMC and SMD) are also called chip components or chip components. They include resistors, capacitors, inductors, semiconductor devices, etc. They are characterized by small size, light weight, no leads or very short leads, high installation density, high reliability, good anti vibration performance, and easy automation.
Photoconductive devices using semiconductor photosensitive characteristics, photocells using semiconductor photovoltaic effect and semiconductor light-emitting devices are collectively referred to as photoelectric devices.
Electronic display device refers to the photoelectric conversion device that converts electrical signals into optical signals, namely, the device used to display numbers, symbols, characters or images. It is the key component of the electronic display device, which has a great impact on the performance of the display device.