First, a quick recap on what they are. Surface mount technology (SMT) is a method of attaching electronic components on to a printed circuit board (PCB). This technique uses smaller components, referred to as surface-mount devices (SMDs) which are used with automated machinery to achieve a significantly higher component density, speed, reliability and consistency in manufacture. Through-hole technology (THT) is a better technique for placing components which require a good resistance to heat, mechanical stresses or may need repairs. This comparison of Surface Mount Technology (SMT) vs Through-Hole Technology (THT) is key for PCB assembly and kitting decisions.
Production volume considerations
PCB complexity
Manufacturing automation level
End product challenging environments – vibration, heat, thermal stress?
Manufacturing flexibility requirements
Sensitive IP
MOQs / NREs / Hidden costs
Why are these important?
In summary, there are many scenarios where investment into SMT makes sense, just as there are many where THT makes sense. Here are some scenarios to help the decision-making process.
A high density of components is required in a small space with complex functionality.
High volume production and speed is required through automation.
Consistency and reliability of manufacture is essential.
Where long production runs of standardised products are required, SMT is a very effective solution as it allows for lower cost manufacturing and greater production capacity and speed.
SMT also benefits products such as consumer electronics where there is a higher density of components crammed into a small PCB, and complex functionality is required.
There are often reworks and small manufacturing runs. Flexibility is required.
Need to keep costs down as limited returns on small runs.
THT would be the better choice because it is better suited to scenarios where there are smaller production runs which may need a degree of flexibility either in the design or in changing over to new production runs without too much cost and disruption. SMT is a large investment and not suited to batch production as it won’t return the investment easily on short runs.
You need to manufacture in reasonably high quantities.
Resistance to mechanical stresses and thermal heating is critical.
Requirement for multiple high frequency applications.
THT would be the right choice for this even though you may have requirements to manufacture in volume. The ability to ensure a more robust mechanical connection and resistance to mechanical stress takes priority. In addition to this, THT would allow easier repairs to components and a higher resistance to thermal heating. The downside is THT does not lend itself well to high frequency applications, so if working in this area it could decrease the performance due to longer leads introducing more inductance.
You need to manufacture in large quantities.
No requirement for thermal stress resistance and low requirement for mechanical stress resistance.
Manufacture well suited to automated pick and place with solder baths.
SMT would be the right choice for this as the requirement for mass production would mean good recoveries. The low requirements for repair and resistance mean that THT would not be required in this situation, and over time, SMT would prove more profitable for the manufacturer.
SMT is a very useful technology for manufacturers who want to create large, standardised production runs and / or want to utilise smaller, more densely populated components. It is also very useful for manufacturers who don’t consistently need to flex and adapt their production to encompass slight design modifications. Applications like consumer electronics, mobile phones and high speed circuits tend to benefit from SMT.
SMT is not the best technology for manufacturing end products which need to have high degrees of thermal or mechanical stress resistance, utilisation or larger components, or regular repair / maintenance around the PCB. Applications such as military, rugged, prototyping tend to benefit more from THT.
Whichever technology you need for your specific applications, Colmworth can assist you with effective kitting and PCBA solutions, reducing the investment required in-house and providing reliable third party supply chain services so you can focus on what really matters. Colmworth Electronics offers expert PCB assembly, kitting, and third-party supply chain services for both SMT and THT requirements.
Get in touch today to discuss your requirements
Colmworth Electronics – 01480 477400
Electronic Component Kitting & Assembly | Colmworth Electronics
