PCB Assembly – Everything you need to know

Source: mokotechnology.com

Printed circuit boards are everywhere around us and we use them daily. We are aware that we can find them in everything around us, starting from our remotes, up to the TV, computer, and even microwave. We have some general idea of how they function but we don’t know anything about the manufacturing process of these components. If you have ever wondered what the assembly process is like for PCB, then you have come to the right place. Here, we are going to tell you everything that you need to know about the assembly process of printed circuit boards and when you finish reading, you will have much more knowledge than now.

What is the assembly process like?

Let’s first talk about the steps of the assembly process and see what happens before we are able to use the PCB. The process starts by first adding the solder paste to the proper place on the board. This has to happen before any components are added so that in the later stages everything can be properly assembled without having to rearrange components and remove them to add the paste.

This whole thing is done automatically using the proper machines and devices, and you need to keep in mind that there are three main types of printed circuit boards and even though the course of the process is similar for them, it is not always the same. There are also flexible and rigid types of boards, and as you can see on uetpcb, the PCB assembly process can differ depending on the exact type of board that is manufactured.

The solder paste is added only in the right holes where the components are going to be paced, and it is not added to the whole board.

Source: electronics-cooling.com

Once that is done the next part of the process is picking and placing the components. The machine or the operator takes these parts from the dispenser and puts them in the right place on the board. Once they are placed on top of the soldering paste, there is no risk of the components moving, and even though the soldering is not yet finished, there is still some tension between the components and the board itself. In some cases, degradable glue has to be used so that the components stay in place, but this is not always needed. Depending on the type of board we are working with, and depending on the type of machine that is used, degradable glue may or may not be used.

The next part of the process is soldering. Once all the components are placed in their rightful place, the machine takes the board and passes it through the soldering device. This is, once again all done automatically, and there is no need for a human worker to do this. Since everything is done automatically in the machine, the risk of injuries is greatly decreased.

When the soldering is finished, the PCB has to be inspected. This is done manually, but it can also be done automatically using the devices at hand. Depending on the production process and the manufacturing factory, sometimes human laborers are employed to do the inspection process by hand, but it can be done inside the machine and every PCB that was not properly soldered or that shows any defects, is being discarded.

Source: mokotechnology.com

The next step of the process is testing. The testing has to happen before these products are placed on the market, and the testing process is done so that it can be checked if there are any mistakes, errors, or defects. The testing process starts by visually inspecting the board as well as the components, and then an analog signature analysis is done. If the boards pass these two stages of testing, then functional testing has to happen. During this process, operators check if the components as well as the PCB itself do everything that they are supposed to do. Finally, in-circuit tests are done to check the frequency, voltage, and many other parameters.

The final step before the PCB leaves the factory is giving feedback on the defective components. In every batch and in every production process there are going to be components that for one reason or another are not functioning the way they are supposed to be. Sometimes the defect can be physical and things may not have been soldered properly. In other cases, everything may pass the visual test, but when it comes to in-circuit testing and checking if every component is functioning the way it should be, there can be a defect. When something like this happens, the operator needs to write a report on what has happened and what the errors and defects are. It is completely expected there to be a few errors in every batch, but if there are a lot of problems with most of the PCBs that are manufactured, that usually shows a bigger issue that has to be resolved as soon as possible.

Is it the same for every board?

Source: ultralibrarian.com

These are the main steps of the PCB assembly process, but they do differ depending on the type of board we need to manufacture. If the board is single-sided, then these are just the steps that need to be followed, if it’s double-sided or multilayered, other things may be included during the process. During the assembly, every stage needs to be done one after the other in the proper order. Steps cannot be skipped, especially when it comes to inspection and testing. Feedback is an as important part of the process as every other part, and if you want to have high quality components that will be fit for your next project, you need to pay attention to who manufactures these boards and how everything is done.

As you can see, there are six main assembly process parts, and they should be the same for every factory, no matter where there are located. If you want to collaborate with a manufacturer that will provide you with high-quality PCBs, then you need to do your research and remember that you don’t have to spend too much money to get the proper equipment and components.