Press-fit holes in printed circuit boards.

Press-fit technology offers a strong and reliable alternative for connecting components to PCBs as an alternative to soldering. Unlike traditional soldered holes, press-fit holes create a mechanical and electrical bond through precision engineering by relying on interference between the component pin and the PCB hole.

This innovation is widely used in industries such as automotive, telecommunications, and industrial electronics, where durability, speed, and environmental compliance are critical.

 

Why Press-fit Holes?

– Durability: Interference alignment creates a moisture-resistant, corrosion-resistant, and vibration-resistant seal, which is crucial for PCBs under the hood of a car or industrial machinery.
– Efficiency: Automatic pressure systems can assemble more than 1000 pins per hour, 2 times faster than manual welding.

– Reliability: eliminates welding defects such as bridges, cold joints, or weld balls, reducing field failure rates by 30-50%.
– Sustainability: it is RoHS and REACH compliant by avoiding lead soldering, in line with global eco-friendly manufacturing trends.

 

 

 

How do press-fit holes work?

Press-fit connections are based on an interference-based mechanical principle, where the component pin (male) is slightly larger than the PCB hole (female). Creating a permanent bond that conducts electricity and resists separation.

Drilling tolerances and hole diameter control must be precise to achieve interference.

Standard tolerances are ± 0.05 mm, with advanced applications requiring ± 0.02 mm (e.g., medical devices).
The insertion force that the pins require is generally 20 ∼ 80 N and for removal, > 50 N avoiding accidental displacement.
Helium leak tests confirm the absence of gaps, which are critical for PCBs in humid or corrosive environments.

The electrical resistance is < 10 mΩ, equal to or greater than the soldered connections.

The success of such a design depends on careful planning of the dimensions.

The size of the pin should be 2.5% larger than the hole, too little (< 1%) causes loose connections.

Standard dimensions are dictated by IPC-2221 guidelines.