The more complex the product is, the harder it is to make. This is why our phones, computers, and home appliances require far more steps to make than any of their predecessors (let alone early electronic devices). So, in theory, it would take longer to make them.
Now, in addition to this, the demand for electronics is higher than ever. After all, in 2024 there will be more smartphones on the planet than people. This is just the tip of the iceberg.
So, how can you make so many sophisticated devices, do it all on time, and ensure that they’re up to an appropriate quality standard?
The answer is through better assembly processes.
Here’s what you need to know about it.
1. PCB assembly
Printed circuit boards (PCBs) are essential to any electronic device. Even a small mistake can lead to a malfunction or a short circuit, which means that if the assembly process isn’t done right, this could lead to a malfunction of the entire application.
Think about it: an entire application could malfunction if any of its PCBs is malfunctioning. This is why the proper methodology of this process is so important.
Generally speaking, there are two methods for PCB assembly that are most commonly used in the industry:
- Surface mount technology (SMT)
- Through-hole technology (THT)
The surface mount technology is a method in which components are placed directly onto the PCB’s surface. This method allows smaller, more compact designs and faster assembly. The best example of this would be to say that it allows you to fit more technology into less space. This makes devices sleeker, more efficient, and less bulky.
Through-hole technology, on the other hand, involves inserting component leads into drilled holes in the PCB and then soldering them. This is a method that provides stronger mechanical bonds. In other words, it’s ideal for products that face high stress or vibration.
So, how do you make an efficient SMT vs THT comparison?
While this is definitely a topic that deserves a more comprehensive explanation, the choice between these comes down to the need for a product. If speed and size are prioritized, SMT might be a clear choice, while reliability and strength favor THT.
2. Soldering process
The next important part of the assembly process is the method of soldering used. You see, soldering itself is important for things like electrical connectivity, mechanical stability, and efficient heat dissipation.
When it comes to the mass production of these parts, you have to choose between hand soldering and automated soldering. Hand soldering is amazing for small-scale projects, where precision and customization are the key. It’s simple and less expensive when you have to handle fewer units. After all, in this scenario, it wouldn’t be cost-effective to set up an automated process.
Automated soldering, on the other hand, is not only faster, but it’s also cheaper (per unit, for a large number of units) and more consistent. If you want every part to come out the same, then a well-set-up automated soldering process is your only solution.
It’s not just who does the soldering that matters, but how it’s done, as well. One technique used in modern assembly is reflow soldering. This technique involves heating solder paste to attach components to the PCB in a controlled environment, ensuring a clean, consistent bond. This method is incredibly delicate and pretty difficult to pull off right.
On the other hand, wave soldering involves passing the PCB over a wave of molten solder and bonding components to the board. It’s ideal for through-hole technology and high-volume production. Just imagine a conveyor belt where everything gets a smooth, even coat of solder in a single go. This makes the process fast and reliable.
The most important thing here is to ensure the reliability of connectors. This is crucial for long-term performance. Whether hand-soldered or done by machine, ensuring solid, clean joints will help prevent issues like short circuits or weak connections. This is like making sure every stitch in a seam is tight.
3. Component placement
When talking about the assembly process, most people are just imagining the process of component placement (especially laymen).
In modern factories, the process is automated, and the machines are now in charge of placing tiny components onto the PCB. This ensures speed and accuracy. The automated pick-and-place systems are handled with the help of robotic arms that drop parts into their exact spot with incredible accuracy. This is much faster and more accurate, especially in environments with a particularly high-volume production.
The key to component placement is the precision in alignment. For electronics to work correctly, each component has to be placed exactly where it belongs. Even the tiniest of misalignments can cause a malfunction. This is like a jigsaw puzzle where, if you place just one piece in the wrong place, it will stick out. It might not seem like it while you’re zoomed into the area but once you take a step back, it will be impossible to miss.
The orientation of components matters just as much as their placement. Sure, some components need to face a specific direction in order to function properly, but others have to be placed at the right angle for optimal performance. The latter example is trickier because it will work either way; it just won’t work as well.
The incorrect placement, in general, will have an impact on performance and failure rates. As we’ve mentioned, it’s not a binary, and if you place it in the wrong place, it won’t work. It might be more prone to malfunctions or work at a reduced capacity.
4. Testing and inspection
When it comes to PCB manufacturing, there’s so much that you just can’t see through visual inspection. It’s not like you’re making toy dinosaurs, and if they come off the assembly line with two heads, you’ve made them wrong. In reality, the differences will be subtle, and the only time you’ll be able to tell is when you either test it or put it to use. It’s far better if it’s discovered during testing.
There are several types of testing you need to be aware of.
First, you have the in-circuit testing (ITC). This means checking each component on the PCB individually in order to ensure it works properly. It’s like making a meal and having to taste each ingredient individually in order to ensure that it’s all evenly cooked.
Then, you have the automated optical inspection (AOI). We’ve already dismissed visual inspection, but the main reason behind this is that these visual marks are too difficult to see. Well, not to an AI-controlled, high-resolution camera. This way, you can spot misaligned components even if the difference is invisible to the human eye.
Next, you should engage in functionality testing. This is where you check if the device works as intended. The simplest way to explain it is just to say that you turn the device on and see how it acts. If it works as intended and doesn’t flicker or produce any noises, that’s it; it’s passed the test.
Just remember that, while new, the tolerance for misbehaving is incredibly low.
5. Quality control
When it comes to electronic components, there are some incredibly strict guides in place.
First of all, for safety reasons. You see, there’s always a risk of electrocution or fire if the device malfunctions. Modern devices have fail-safes in place, but if something doesn’t work as intended, you’re in a problem.
Then, it’s important to understand that your average customer isn’t an electrician. This means that they don’t really understand the product they’re buying, and they can’t pass judgment on how good it actually is. Therefore, there are some strong laws designed to protect the consumer.
Lastly, these devices are often expensive, and by ensuring they’re up to standard, companies save themselves from a lot of cashback instances, complaints, and even lawsuits.
So, how is this quality control done?
First, there are certain standards for manufacturing of electronic components. This is a rulebook that manufacturers have to follow, and when you start testing, you don’t have to start with the product; you observe the process and correct irregularities.
Next, you have the statistical process control (SPC), which is the use of data to monitor and control processes. By tracking metrics, manufacturers can detect variations and address issues before they escalate.
Other than that, you could analyze the root causes of failures. This is why the post-sale life of a product is so important and why CRM makes such a difference, although you would ideally notice this during the testing stage. When something goes wrong, manufacturers need to perform a root cause analysis to figure out what happened.
Electronics depend on an efficient assembly process
With the highest demand for electronics in history, there’s no room for error in the assembly process. Every step needs to be executed flawlessly, and there’s no room for compromise. Luckily, with modern techniques and automation, this is no longer a mission impossible.
