PCBA Manufacturing Process

The modern-day electronics world depends heavily on the Printed Circuit Boards (PCBs) as its backbone. The miraculous invention has paved the advancement of electronics of all sorts. A PCB is a medium to transfer the current through its copper pathway and it dissipates the heat to keep the tiny yet highlycomplex electronic equipment on it in perfect condition.

The PCBs are arranged with various electronic components such as ICs, transformers, transmitters, etc. Once the PCB is mounted with these components, it is called the PCBA. Hence, the PCBA manufacturing process follows solder paste, picking and placement of the component, soldering, and final inspection stages.

If you are to get the best PCBA and PCB for your digital devices, you have to know this PCB assembly process thoroughly. FX PCB with its years of experience understands this need and thus, we present you the detailed guideline on the printed circuit board assembly process.

Table of Contents

What Is The Difference Between PCB and PCBA?

During our long working time in the PCB industry, we have seen a majority of people considering the PCB and PCBA the same thing. Thus, before we move to the PCBA manufacturing steps, let’s clarify the confusion you have.

The PCB is a bare substrate with copper or other metal on it working as a base to dissipate the heat. Also, it transfers and transmits data electronically. When a PCB is built, it is a bare component.

During the PCBA manufacturing, this bare PCB will be used as a base to mount various electric components. The list includes transistors, resistors, ICs, transmitters, etc. Once you mount the electric components on the PCB, it is called the PCBA.

You have to use soldering to complete the PCB assembly.

Steps to Follow For the PCBA Manufacturing Process

Almost all PCB and PCBA manufacturers follow a standard process to manufacture the PCBA. FX PCB is no exception to it. Our process includes solder pasting on the PCB base, placing the electronic components in the right place, soldering them with the PCB, checking the accuracy, final inspection, and delivery to customers.

The entire process is monitored closely to ensure 100% accuracy in the manufacturing process. Also, the automated engineering makes sure the entire steps are fast and quick for on-time delivery.

Solder Pasting:

When you get the PCB at hand, the temptation is high to instantly add the components to it. But, it is not possible and neither is a practical idea. You have to inspect the printed circuit board and add solder where it is essential.

Typically, you have to add the solder on the component pads using the solder screen.

If you don’t know what solder paste is, here’s the short answer-

It consists of flux and small solder grains to form a paste. The deposition of the solder paste on the specific process is similar to the printing process. Firstly, the solder screen will be placed right where you want to add the solder paste. The screen has a hole in it to see through it into the PCB. Then, a runner will move over the solder screen.

Finally, a small amount of solder paste will go through the screen hole and sit right over the PCB substrate. You have to control the solder deposition to ensure that the component pad isn’t clogged with too much of the solder paste.

Pick and Placement Process:

This process has two steps to follow-

  1. Adding the solder paste properly to hold the components.
  2. Passing the entire circuit board into the pick and place process.

The solder paste uses its tension and adhesiveness to accommodate the components right in their positions without movement. Also, you have to ensure that the circuit board isn’t jolted or the components will move and get out of their positioning.

Then, at the final stage, the circuit board passes through the pick and place machine. It has reels holding the components. As the circuit boards pass through it, the reel will correctly position the electronic components on the board. It follows the pre-designed model for each PCBA.

Some machines will add glue in doted form for additional security of the components. It is especially essential for wave soldering. Although the connection between the components and the circuit board is made secure with the glue, it makes any repairing process difficult.

You will have to drive the PCBA design information and program it to the pick and place machine properly. Otherwise, the assembly won’t be accurate.

Soldering Process:

Once you have added all the necessary electric components on the circuit board using a pick and place machine, you have to solder them. Our engineers and workers will pass through the component added PCB through the automated soldering machine.

Many manufacturers will use the wave soldering process but these days it has become an outdated process. More importantly, the surface mount components (SMC) aren’t best for wave soldering. Hence, most PCBA manufacturers use the reflow soldering technique.

Note: If the assembly follows wave soldering, it doesn’t need any solder paste processing. The wave solder will add the essential soldering material to the circuit board.

Testing and Feedback:

Once the soldering is complete, the entire assembly of the PCB to its components is thoroughly observed and checked. The manual inspection isn’t a valid option here. The Surface Mount Components (SMC) has hundreds of various components and you can’t manually check them.

FX PCB uses automatic optical inspection (AOI) for the detailed and mostaccurate inspection of the soldered components. There are inspection machines that will check the soldering joints and report where the components need re-soldering.

Finally, the entire PCBA setup is tested before delivery. There are multiple ways and methods for testing the entire PCBA setup. Also, it is essential to monitor the component outputs after soldering. It will decide whether or not the entire assembly process is satisfactory.

The manufacturers use the optical inspection to find if the assembly has any connection failure. Once the inspection is completed and the performance is satisfactory, the PCBA is packed for delivery.

Final Words

In this guideline, we have simplified the PCBA manufacturing process, thanks to our engineering output. The entire process is optimized to keep the defects at the lowest level. Hence, FX PCB follows the standard and exceeds it to offer you the highest-quality PCB and PCBA manufacturing at the most competitive pricing.

You can perform loads of device production with the PCB assembly and boost your business with flawless PCBAs for durable performance.

Peter Gong
Peter Gong

I am Peter Gong. I have been working in PCB and PCBA industry for 15+ years now. I have been a part of the PCB revolution with my dedication to circuit board technologies and creative ideas. I write in FX PCB to impart my knowledge on PCB and PCBA for all circuit board lovers, manufacturers, and users.