PCB Assembly Process

PCB Assembly Process

Firstly, take you to know some brief development history of PCBA, also called PCB assembly. PCBA is the abbreviation, which means that the SMT process of the PCB finished or the process of passing through the DIP or THT. Then it is abbreviated as PCBA. In fact, it is commonly referred to as an electronic board or circuit board.

Circuit board, abbreviated as PCB, is an important electronic component and the support of electronic components. This is the earliest version. Later, the Austrians created new technologies that removed unwanted metals and added wiring, forming the version we are currently using.

Due to its position in the latter half of the electronic equipment process, PCBA is referred to as the downstream of the electronic industry. Because all electronic devices and equipment require PCBA’s support, this project has the highest portion in the electronic market. There are currently huge industrial areas around the world that manufacture circuit boards (PCB).

Computers and related products, communication devices, and electronic devices are all the main consumer groups of PCBA. Including commonly computers used at home, televisions, LED lights, mobile phones, tablets, etc. Because every household is using it, PCBA’s economic development is rapid and it has quickly become the top in the world.

PCBA is still developing, and to make people’s lives more convenient, there are several general conditions for its development:

a. Vigorously develop HDI to make PCBs more precise and smaller.

b. PCBA also needs to ensure strong vitality and service life in order to last longer.

c. Update production equipment and manufacturing process.

In PCBA processing, SMD components and plug-in (THT, Through-hole technology) components are used.

Chapter 1: SMD components and plug-in (THT) components

So, what is the difference between SMD components and plug-in (THT) components?

1、 The difference between the two are as below:

1.1 SMD components have small size, light weight, and are easier to solder than plug-in components.

1.2 One important benefit of SMD components is that they improve the stability and reliability of the circuit; Because the SMD component has no leads, it reduces stray electric and magnetic fields, which is particularly effective in high-frequency analog circuits and high-speed digital circuits.

2、 Soldering method for both

2.1 Method for soldering SMD components:

Place the component on the solder pad, apply the prepared SMD solder paste on the surface of the component and the contact area between the solder pad, and then heat the connection between the solder pad and the SMD component with a 20W internal heating electric soldering iron (the temperature should be between 220~230 ℃). Once the solder melts, remove the electric soldering iron and wait for the solder to solidify before welding is completed. After welding, tweezers can be used to clamp the soldered components to see if there is any looseness. If there is no looseness, it means that the soldering is good. If there is looseness, reapply solder paste and weld again according to the above method. 

2.2 Method for soldering THT components:

When soldering all pins, solder shall be added to the soldering iron tip, and flux shall be applied to all pins to keep them wet. Touch the end of each pin of the chip with a soldering iron tip until the solder flows into the pins. After all pins are soldered, wet the pins with flux to clean the soldering tin, so as to eliminate any short circuit and overlap. Finally, use tweezers to check whether there is faulty soldering. After the inspection, remove the flux from the circuit board and carefully wipe the hard brush along the pin direction with alcohol until the flux disappears.