Why is SMT better than through-hole?
Although selecting electrical components for a new PCB can be a tedious task, it is undeniable that it is very important. Designers need to view dozens or even hundreds of variants of parts and check current inventory, future availability and replacement parts. All these choices and considerations are very important, but before choosing components, we need to consider a more basic question: surface mount technology (SMT) or through-hole? Many people think that through-hole devices are old-fashioned, while SMT is a modern style. Although this is true for many applications, through-hole technology still has some clear advantages in some cases. Through-Hole Assembly performs well in circuit boards that withstand high mechanical or thermal stress and have high power requirements. On the other hand, SMT is more suitable for small size.
The advantages and disadvantages of Through-Hole Assembly
If you open a random consumer electronic device today, you may not find a lot of Through-Hole Assembly inside. This does not mean that they no longer have a place in the PCB world. It's just that most circuits today don't need their unique advantages. Through-hole devices are also excellent in applications that have strict physical requirements. These applications also have high requirements for heat or power, and can be used for prototyping. However, they are not very useful on small boards that require cheap pcb manufacturing.
When it comes to strict thermal and shock requirements, the secret of through holes lies in the soldering process. Through-hole components have long leads that are inserted into holes in the PCB and then soldered to the copper pads. This connection method is much safer than SMT style installation, and can make the through-hole board withstand greater physical and thermal stress. On average, through-hole components are also larger than SMT components, which means they can usually handle higher power applications. Another advantage of the through-hole welding method is that it is easier to disassemble and replace the prototype iteration of the component during the installation process. If you need to dry other variants of some components, simply remove them and solder them.
All these advantages are accompanied by costs, mainly in terms of Quick-turn PCB fabrication, low cost pcb manufacturing and Quick Turn PCB turnaround time. SMT components can be placed on the PCB faster than through-hole devices. Circuit boards with Through-Hole Assembly also need to be drilled, and these two requirements will lead to higher circuit board costs. Through-hole components are also physically larger than SMT devices and can only be soldered to one side of the board. Therefore, if you need cheap pcb manufacturing, Through-Hole Assembly may not be suitable for you.
Advantages and disadvantages of SMT equipment
SMT devices are very small, faster to place, and can be mounted on both sides of the PCB, so that the manufacturing cost of the SMT board is greatly reduced. The assembly process is not always smooth, because Surface-Mount (SMT) & BGA Assembly may encounter many problems during the manufacturing process.
If you need to manufacture cheap, small and lightweight PCBs, SMT components may be the right choice. They are much smaller than through-hole devices, so they are much lighter. Tiny components mean dense placement on the PCB, and many electronic products today focus on size, so this advantage is hard to beat. The physical form of SMT components also facilitates faster placement during assembly, thereby reducing costs throughout the product's life cycle.
Despite its obvious advantages, SMT manufacturing still faces a series of unique challenges. Although components can be placed faster, the machinery required by PCBA Manufacturing is very expensive. Such a high capital investment in the assembly process means that SMT components can increase the cost of small-volume prototype boards. Due to the increased complexity of mounting, surface-mounted components require higher precision wiring blind via hole PCBs and buried PCBs instead of through-hole PCBs during the manufacturing process. In the design process, accuracy is also important, because violating the contract manufacturer (CM) DFM pad layout guidelines may cause more and more problems, such as logic deletion, which may greatly reduce the yield during the production process.
When should I use surface mount technology (SMT) and through holes?
Although SMT is a newer, more compact component packaging style, and through holes are more suitable for larger circuit boards, both mounting methods will not disappear soon. Each option has unique advantages that can help you determine the best design for you. If you are designing military-grade PCBs or delving into critical system design involving demanding physical and thermal requirements, you may need to use through-hole components. If you want to make the next small consumer electronic device where every detail is critical, then SMT equipment may be for you. No matter which style you decide to adopt, Beat Automation will be ready to bring your PCB to life.
