Surface mount technology and through-hole technology are the main PCB manufacturing methods. Choosing between these assembly methods often comes down to which components are better for your product: SMDs (surface mount devices) or through-hole components. Each has it benefits, depending on the end use of the PCB.
Surface mount technology and through-hole technology are the main PCB manufacturing methods. Choosing between these assembly methods often comes down to which components are better for your product: SMDs (surface mount devices) or through-hole components. Each has it benefits, depending on the end use of the PCB.
Electronic devices are designed for human use, and our interactions with electronics are rarely gentle: we drop them, have them bounce around in bags and vehicles, open and close them repeatedly, tap and poke them, and generally treat them roughly.
This is where through-hole components have the most advantage: they are mechanically stronger than most SMDs because their leads run through the board, allowing them to withstand more environmental stress. Heavy, high-power, or high-voltage parts (such as transformers) are best secured via through-hole technology to ensure they can withstand mechanical stress and high heat.
Through-hole components are perfect for products that may experience extreme accelerations, high temperatures, or collisions, which is why they are commonly used in the automobile, aerospace, and military industries. Through-hole components are also useful for testing and prototyping because they can be manually adjusted or replaced with relative ease.
The drawbacks of through-hole components are that they require holes to be drilled in the board, which can be expensive and time consuming. Since the holes go through all of a PCB’s layers, they also limit the available routing area on multilayer boards. Lastly, the soldering techniques used on through-hole components are less reliable and repeatable than those used for SMDs.
While through-hole components get their strength from the board itself, the strength of surface mount devices is limited to the solder joint holding them to the surface of the board. The smaller the part, the less solder is used, thus limiting the strength of the bond. Thus surface mount technology (SMT) is unsuitable for large, high-power, or high-voltage parts, or as the sole attachment method for components frequently subjected to mechanical stress.
The advantages of surface mount devices are that they allow for smaller PCB size and higher component density. SMT boards are also faster and less costly to produce. This is the because the boards do not have to be pre-drilled; components can be placed at rates of thousands - or tens of thousands - per hour; and SMT soldering is more reliable and repeatable than through-hole soldering.
At Telan, we have been producing high-quality, reliable PCBs for over three decades. Whether your product needs SMDs or through-hole components, we can assemble your board quickly. Call us today at 215-997-7603 for more information on our assembly services.