When it comes to PCB Assembly Techniques, 3 basic technologies find their applications for the modern-day electronics industry. These include:
- Through-Hole Technology (THT) Assembly Process
- Surface Mount Technology (SMT) Assembly Process
- Mixed Technology
Let us look at each of them in some detail:
Through-Hole Technology (THT) Assembly Process
This method of constructing electronic circuits involves inserting pin-through-hole components through holes that are drilled into the PCBs (Printed Circuit Boards). The ends are then affixed by way of molten solder.
The steps in Through Hole PCB Assembly include:
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Placement of Components
As the name suggest, this step involves placing the components precisely in accordance with the PCB design files. It is imperative that the placement of components conforms to the best practices of through-hole mounting to ensure reliability.
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Inspection
A rigorous inspection process to ascertain that the components are correctly placed follows. This process ensures that any changes can be immediately made and costly errors prevented.
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Wave Soldering
Now is the time to solder the components onto the circuit board. The wave soldering method involves bringing the solder to a temperature of around 500-degree F and having the board move over it slowly.
Overall, through-hole PCB technology came as the much-needed replacement for techniques such as point-to-point construction, which were in use in modern electronics.
Surface Mount Technology (SMT) Assembly Process
This technology allows the components to be mounted directly on to the surface of the printed circuit boards with solder paste. This technology works for small components. The various steps involved in the SMT process include:
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Solder Paste Printing
This process involves using a solder paste printer and stencil to ensure that the solder paste is correctly applied on areas where the components need to be mounted.
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Components Mounting
The PCB is next sent to a pick-and-place machine where the components are mounted on the board, which in turn, stick to the board on account of the solder paste.
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Reflow Soldering
The board now passes through a reflow oven, which has a temperature of over 500-degree F. This enables the solder paste to melt. The melted solder is then cooled till strong joints between the components and the surface of the board are formed.
The key advantage that surface mount technology brings is that it lends itself to small and lightweight PCBs, which in turn, work well with the trend of miniaturization that has taken the electronic world by storm.
Also, as compared to the through-hole process, with its high degree of automation, surface mount technology lends itself to a high degree of accuracy besides keeping labor costs in check. Additionally, the drilling that through-hole mounting entails makes the boards more expensive to produce while also limiting the routing area for signal traces. While through-hole technology is used for bulkier components that are in need of added mounting strength, little surprise then that through-hole technology finds application in not just PCB for electronics but also telecommunications, aviation and more.
Mixed Technology
With the complexity in electronic products on the rise, mixed technology boards where both SMD and through-hole components are used, is also on an increase.
A mixed assembly involves using a combination of methods. Mixed technology assemblies could be by way of:
- A single-sided mixed assembly, where both surface mount technology as well as through-hole technology is used on the same side of the board.
- A split assembly, where one side of the printed circuit board is assembled with surface mount technology and the other side of the board is assembled with through-hole technology.
- A double-sided mixed assembly, where both sides of the printed circuit board are assembled with a combination of through-hole technology and surface mount-technology.
A PCB with mixed technology needs thorough inspection by way of an Automatic Optical Inspection, which points out any imperfections.
Mixed technology finds extensive application in:
- Communication hardware
- Server Boards
- LED lighting products
- Video processing, and more
To sum up
In conclusion, as electronics become smaller and more complex, so do PCBs that power these devices. For Electronics PCB Assembly it means making use of advanced levels of engineering to offer reliable products.
Mer-Mar Electronics offers a multitude of PCB Assembly services that range from components’ procurement, fabrication, assembly, testing, and delivering the best quality end products to our customers. We have a team of professional engineers and technicians who will closely collaborate with you to ensure superior quality products are delivered in the quickest time possible. Through the fulfilment of several orders on a frequent basis, we’ve established ourselves as the leading supplier of PCB Assembly.
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