PCBA Tech - About PCBA processing components and operation methods

PCBA passes through SMT on the empty PCB board, and then goes through the production process of DIP plug-in. It will involve a lot of fine and complicated process and some sensitive components. If the operation is not standardized, it will cause process defects or components. Damage, affecting product quality and increasing processing costs. Therefore, in the PCBA patch processing, it is necessary to comply with the relevant operating rules and operate in strict accordance with the requirements.

Operation rules of PCBA patch processing:

1. There should not be any food or drink in the PCBA work area, smoking is prohibited, no sundries unrelated to work should be placed, and the workbench should be kept clean and tidy.

2. The soldered surface of the PCBA patch cannot be taken with bare hands or fingers, because the grease secreted by human hands will reduce solderability and easily lead to soldering defects.

3. The operation steps for PCBA and components are reduced to a minimum to prevent danger. In assembly areas where gloves must be used, soiled gloves will cause contamination, so gloves must be replaced frequently when necessary.

4. Do not use skin-protecting oils to coat hands or various silicone-containing detergents, as they can cause problems in solderability and adhesion of conformal coatings. A specially formulated detergent for PCBA soldering surface is available.

5. Components and PCBA that are sensitive to EOS/ESD must be marked with appropriate EOS/ESD marks to avoid confusion with other components. In addition, in order to prevent ESD and EOS from endangering sensitive components, all operations, assembly and testing must be completed on a workbench that can control static electricity.

6. Regularly check EOS/ESD workbenches to confirm that they can work normally (anti-static). The various dangers of EOS/ESD components can be caused by incorrect grounding methods or oxides in the ground connection parts. Therefore, special protection should be given to the "third line" grounding terminal joints.

7. It is forbidden to stack PCBA, otherwise physical damage will occur. There should be dedicated various brackets on the assembly work surface, and they should be placed according to the type.

PCBA patch processing mainly includes two major processes: PCB circuit board production and SMT patch processing. Electronic components are inevitably used in the middle. Electronic components are the basic part of PCBA patch processing and also affect the performance and quality of PCBA finished products. Key factor. So what are the commonly used electronic components in PCBA patch processing? The following Jingbang technicians will organize and introduce for you.

1. Resistance

Resistors are electronic components with resistance characteristics and are one of the most widely used components in PCBA. Resistors are divided into fixed resistors and variable resistors (potentiometers), which play the role of voltage division, current shunting and current limiting in the circuit.

2. Capacitor

Capacitor is also one of the basic components in PCBA processing. It is a component that stores electrical energy and plays the role of coupling, filtering, DC blocking and tuning in electronic circuits.

3. Inductance coil

Inductance coil is abbreviated as inductance, which has the function of storing magnetic energy. Inductance coils are usually composed of bobbin, winding, shield, magnetic core and so on.

4. Potentiometer

A resistor whose resistance value can be changed, that is, a resistor that can be continuously adjusted within a specified range, is called a potentiometer. The potentiometer is composed of a shell, a sliding end, a rotating shaft, a ring resistance body and 3 lead-out ends.

5. Transformer

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 winding, and the remaining windings are called the secondary winding.

A transformer is a device that transforms voltage, current, and impedance. When an alternating current is passed through the primary coil, an alternating current magnetic flux is generated in the iron core (or magnetic core), causing a voltage (or current) to be induced in the secondary coil. Transformers are mainly used for AC voltage conversion, current conversion, power transfer, impedance conversion and buffer isolation, etc., and are one of the indispensable important components in the PCBA machine.

6. Crystal diode

Crystal diodes (ie semiconductor diodes, hereinafter referred to as diodes) are made of a PN junction, electrode leads, and an externally sealed tube case. It has unidirectional conductivity.

7. Transistor

Transistor (hereinafter referred to as triode) is the core device for signal amplification and processing, and is widely used in PCBA complete machines.

8. Field effect tube

The field effect transistor (referred to as the field effect tube) is also a kind of semiconductor device with a PN junction. Unlike the triode, it does not use the conductivity characteristics of the PN junction, but uses its insulation characteristics.

9. Electroacoustic device

The devices used in the circuit to complete the conversion between electrical signals and sound signals are called electro-acoustic devices. It has a wide range of types, including speakers, microphones, earphones (or earplugs), microphones, receivers, and so on.

10. Optoelectronic devices

Photoconductive devices that use semiconductor photosensitivity, photovoltaic cells and semiconductor light-emitting devices that use semiconductor photovoltaic effects are collectively referred to as optoelectronic devices.

11. Display device

Electronic display devices refer to photoelectric conversion devices that convert electrical signals into optical signals, that is, devices used to display numbers, symbols, text or images. It is a key component of an electronic display device and has a great impact on the performance of the display device.

12. Sensor

A sensor can sense a device or device that is measured and converted into a usable signal according to a certain rule. It is usually composed of sensitive components and conversion components.

13. Surface mount components

PCBA surface mount components (SMC and SMD) are also called chip components or chip components, which include resistors, capacitors, inductors and semiconductor devices, etc., with small size, light weight, no leads or very short leads, High installation density, high reliability, good anti-vibration performance, easy to realize automation and so on.

14. Thyristor

SCR is the abbreviation of SCR rectifier element. It is a high-power semiconductor device with a four-layer structure with three PN junctions, also known as a thyristor. It has the characteristics of small size, relatively simple structure, and strong functions. It is one of the more commonly used semiconductor devices.

15. Switches, relays, various connectors

Switches are used in electronic equipment to cut off, connect, or switch circuits. A relay is an automatic control device whose output will change leaps and bounds when the input (electricity, magnetism, sound, light, and heat) reaches a certain value.