What You Should Know About the PCB Assembly Process
Every electrical device in use today has a printed circuit board (PCB) that allows it to function. Whether we’re talking about smart speakers for the house, your new smart thermostat, or your car’s digital speedometer, the PCB is at the core of electronic gadgets. Creating working electrical devices, on the other hand, involves far more than simply connecting a few components and resistors.
The PCB assembly procedure must be done correctly the first time. A single blunder here might lead to faults, loss of functioning, and even the risk of an accident. We’ll go through some of the most crucial PCB assembly process phases and what you should be aware of in this post.
It’s Not Board Manufacturing
To begin, recognise that the PCB assembly process occurs at a precise point in the construction of an electrical device. It’s not about production; that comes first. For example, at Advanced Circuits, we’ll start by manufacturing the board itself, which includes all of the essential layers, tracing, and other key stages, before moving on to PCB assembly.
In a nutshell, PCB assembly is the act of bringing everything together in one spot and making something useful out of a collection of parts. It entails taking a freshly built board, adding components and resistors, and ensuring that it performs as planned.
Understand the Pcb Assembly Technologies
More than simply the raw components and a well-designed board are required to assemble a printed circuit board. It also necessitates the use of appropriate technologies. In this scenario, there are various choices to choose, each of which offers something unique. There’s surface mount technology (SMT), hand soldering, and the use of pick and place machines, for example.
While certain PCB assembly procedures will only require one technology, others will necessitate the use of two or more. Many boards, for example, necessitate the use of both through-hole and surface mount technologies. When selecting a business to manage your project or production, knowing when, when, and how to incorporate such technologies is crucial.
It’s also vital to note that the PCB assembly processes used by the various technologies differ. We’ve listed some of the basic stages below, as well as how they alter depending on the technology.
An Overview of the PCB Assembly Process
Solder Paste: The application of solder paste is the first stage in the traditional PCB assembly process. Although this is not the case with THT, SMT does necessitate the use of paste and/or printing.
Placement of Components: The next stage in the typical PCB assembly process is to instal the components on the board. This can be accomplished manually or with the aid of machines (pick and place systems). Components are positioned by hand in THT assembly, which necessitates extreme accuracy. Robotic systems instal components on the board during the SMT process. It’s worth noting that automatic placement is both faster and more exact than hand placement.
Reflow: The next phase in the typical PCB manufacturing process is reflow, which involves melting the solder and then resolidifying it. The board and all of its components pass through an oven, which warms the solder, liquefies it, and ensures that connections are created before passing through a cooler, which cools the solder.
It’s worth noting that the THT method does not necessitate reflowing solder. Instead, the next step is to review the board and make any necessary changes to component arrangement. This is owing to the hand placement procedure; a visual examination, along with the use of a design transport frame, helps assure placement correctness.
In the SMT process, reflow soldering is also done at this point. The board is heated in a furnace, which melts the solder paste and allows it to flow as needed, before passing through a series of coolers, which progressively lower the temperature, hardening the solder on the board and cementing the components in place.
Inspection: Visual examination of the board, soldering, and components is the next phase in the traditional PCB assembly process. This phase has already taken place in the THT and SMT procedures.
Through-Hole Part Insertion: The traditional method necessitates manual through-hole insertion following the reflow and inspection processes. Soldering is usually done by hand, however it can also be done by wave soldering.
At this step in the THT process, wave soldering takes place. The entire board passes through liquid solder before being cooled to harden the solder.
In the SMT process, there is no corresponding phase (it is actually already finished, and wrapped up after just three steps, although a visual inspection should still be conducted to ensure accuracy and to reduce the potential for errors).
Final Examination and Cleaning: The typical PCB assembly process concludes with a final inspection of the board, solder points, and components, as well as a cleaning to remove any dirt or excess solder.
The Right PCB Assembly Process for You
While SMT assembly is generally faster and more precise than traditional PCB assembly or THT assembly, it is not always the best solution. For example, if you just need to manufacture a single prototype board, the THT technique could be the superior option. Each circumstance is unique, and there is no one-size-fits-all solution that will always meet all requirements.
Extron recognises that everyone’s demands, finances, and objectives are different. We take pleasure in providing precisely the solutions that each client requires. We can assist you in developing a single prototype for proof of concept purposes or thousands of units for full production. To book a consultation or learn more about our services and expertise, please contact us today.