Understanding the Role of Surface Mount Technology in Circuit Board Assembly

Also known as SMT, surface mount technology is soldering various parts of the circuit board directly onto the circuit board. It is considered a breakthrough in the PCB industry, mainly due to its benefit of cutting costs without cutting corners on quality.

SMT comes under the electronic component assembly phase of the circuit board construction, and this technology is designed to be directly mounted onto the actual circuit board.

Let us delve deeper into this technology, understanding what SMT is in greater detail and looking at the manufacturing process in further detail.

Surface Mount Technology: Explained

This piece of technology is utilized during the assembly of the PCB and is a production method that involves directly embedding various electrical components onto the PCB.

The main selling point and a major reason why this is considered such a beneficial technique for PCB production are that the entire circuit board creation process can now be fully automated

 because of how it works. 

The parts installed onto the PCB are surface-mounted devices or SMD.

How does it work?

What makes SMT an upgrade is that it eliminates the time-consuming process of mounting components onto the board by making holes to insert them in.

Using SMT, you can solder the parts directly onto the PCB using a technique called reflow soldering, shedding a great amount of time that would be spent when assembling the board using the conventional production method.

However, circuit boards made through SMT are usually automated by integrating different machinery into the production process. The overall process can prove to be time-consuming because of the precision required when soldering the parts onto the spots on the board.

Incredibly high precision and accuracy are required when installing the parts into the circuit board through this method, which is why special machinery is developed known as surface mount assembly.

 Applying parts onto the circuit board using SMT is required primarily since this technology involves incredibly small components compared to the components which are fit using the through-hole assembly method.

PCB Manufacturing Process using SMT

1. Prepping the Board and Necessary Components

Before soldering any component onto the circuit board, performing certain tasks to prepare them is usually handled during the board, component, and board design stage.

The initial state of the PCB comprises a board that comprises a copper or gold pad, also known as a solder pad.

Stencils are a vital tool used during manufacturing to provide each component with a set position, which is necessary for the paste printing process.

2. Solder Paste Printing

This is a vital phase of the SMT manufacturing process, where a special printer applies paste onto the predetermined positions set using the stencil. Ensuring the paste is applied to the correct positions is vital because it holds the mounted components in place.

3. Applying the Components

After solder paste has been applied to the different spots and the board has been prepared, it is time for the components to fit onto the board using SMT.

Special machinery ensures that the devices are mounted precisely onto the position assigned to each of them. Since the boards are moving on a conveyer belt, with each machine working by applying a part on the board while the PCB moves, accuracy is vital.

4. The Reflow Soldering Process

Once the SMCs have been installed onto the circuit board, the conveyer belt takes the PCB through the soldering oven comprising different zones. This soldering method is designed to accelerate the setting and drying process to ensure that the solder has been applied and the components have been set in place as soon as possible.

5. Thorough Inspection

After the PCB has been fully assembled, it goes through cleaning, and a final inspection is made to check for possible flaws or defects that might occur during the assembly.

Conclusion

Judging by the information above, surface mount technology has successfully automated the entire PCB production and manufacturing process, which is mainly why it is considered such a breakthrough in PCB assembly.