QPE Blog: Through-hole assembly: when it is the right choice for your PCB

Surface Mount Technology (SMT) supports compact, densely populated PCB designs, but through-hole assembly continues to play an important role in electronics manufacture.

Connectors, transformers and certain power components often use through-hole mounting. It can also be suitable for parts exposed to mechanical loads, where the way a component is secured to the board is an important design consideration.

At QPE, our through-hole capability supports products that require this approach, including mixed-technology assemblies combining through-hole and surface-mount components.

How through-hole assembly works

Through-hole components have leads or pins that pass through holes in the PCB and are soldered to the board. Plated through-hole (PTH) construction provides a conductive connection through the hole.

The component’s mounting arrangement can provide mechanical strength alongside its electrical connections. This can be useful for parts such as connectors that experience forces during plugging and unplugging.

The suitability of through-hole mounting depends on the component, board design and operating conditions. It is one of several considerations when choosing how an assembly should be manufactured.

Where through-hole components are used

Through-hole mounting remains relevant for a range of components and applications, including:

• Connectors that need to withstand repeated handling or mating.

• Transformers and larger components whose size and weight influence mounting requirements.

• Power components supplied in through-hole packages.

• Parts subject to mechanical loads, where secure attachment is a priority.

  
  

The choice is driven by the product’s requirements. Through-hole assembly offers useful characteristics where the design calls for them.

Supporting mixed-technology assemblies

Many PCBs combine surface-mount devices with through-hole components. A board might use SMT for much of its circuitry while retaining through-hole connectors or power components.

These assemblies require both processes to be planned together, taking account of component access, assembly sequence and soldering requirements.

QPE’s SMT and through-hole capabilities allow us to support these mixed-technology builds within a coordinated manufacturing process.

What this means for customers

For customers, through-hole capability provides flexibility to use the components and mounting arrangements suited to their products.

It also allows mixed-technology designs to be manufactured by a team experienced in both assembly methods, with inspection and testing requirements considered as part of the build.

At QPE, we tailor our manufacturing approach to the assembly’s specification and application. Through-hole assembly remains an important part of that capability, supporting products where component selection and mechanical requirements call for it.

Does your PCB use through-hole components or a combination of assembly technologies? Contact QPE to discuss your manufacturing requirements.