If you’re sourcing PCB assembly at scale, the manufacturing method matters. Surface Mount Technology (SMT) and Through Hole Technology are two tried and tested approaches, but they offer different benefits depending on the complexity, environment, and application of your build. So, which is right for your product?
What Is Surface Mount Technology (SMT)?
SMT places components directly onto the surface of a PCB. The process is highly automated and well suited to large volume production. Because SMT components are smaller, more of them can be placed on each side of the board. This allows for compact, high-functioning designs with more flexibility in layout.
SMT is widely used in consumer electronics, industrial equipment, telecoms and automotive applications. If your build needs high speed production, space saving designs, and supports automated assembly, SMT will likely be the go-to.
Benefits of SMT:
- Supports smaller, more lightweight boards
- Allows for faster production rates
- Compatible with high pin-count components
- Reduces manual labour and associated error rates
What Is Through Hole Technology?
Through Hole Technology involves inserting component leads into drilled holes and soldering them to the other side of the board. It’s a more traditional approach, offering mechanical strength and strong component anchoring.
Unlike automated Surface Mount assembly, Through Hole still requires a human touch. Skilled technicians are needed for both the design and hand-soldering stages, especially when working with complex or stress-bearing components. In an industry increasingly leaning into automation, this keeps hands-on expertise alive and underlines the continued value of manual precision.
Through Hole is often used in aerospace, defence, or high-voltage industrial systems, particularly for connectors, large capacitors or components subject to physical stress.
Benefits of Through Hole:
- Provides strong mechanical bonds
- Ideal for harsh environments or where components experience force
- Reliable for high voltage or high power applications
- Easier to test and replace individual components
SMT vs Through Hole: What Influences the Choice?
The decision often comes down to a few key factors:
- Volume and speed: SMT is far more efficient for large runs and high throughput
- Board design: Complex multi-layer boards benefit from SMT’s space-saving footprint
- Durability requirements: Through Hole adds strength for components under stress
- Component type: Some components, like large transformers or mechanical switches, are still better suited to Through Hole
- Cost efficiency: While SMT has higher setup costs, it becomes more cost-effective at scale
Some projects benefit from a hybrid approach, combining SMT for most components with Through Hole for selected parts. The key for this type of hybrid build is to try and get all the components on the same side to enable wave soldering.
Why It Pays to Get Advice Early
A good PCB design should account for optimal performance, but it also needs to consider how the board will be manufactured, tested and assembled at scale. The right choices made early in the process can reduce redesign costs and improve lead times.
That’s why we work closely with our clients from the outset, advising on the most suitable assembly method to match both technical requirements and commercial goals. Whether you already have a detailed bill of materials (BOM) or you’re still scoping out your build, we’ll help you make the right call.
We have a lean, process led, highly efficient line production facility with high capacity pick and place SMT machines, in-line Automated Inspection, lead free wave solder and a highly experienced team to maximise the efficiency of the assembly equipment. Contact us to learn more about our PCB assembly services.
Ask about our PCB design guidelines, we would be more than happy to send you a copy.