Are surface mount or through hole connections more reliable for safety critical applications?

Factors like safety certifications and margins of error are more important when it comes to safety critical applications, e.g. aerospace. Lots of content online have showed the pro and cons of SMT and THT. But is there a straight-forward winner between these two?

While not a definitive answer, every recent (last 20 years) military and space product I’ve worked on has been built using SMT (Surface Mount Technology).

There were some exceptions for individual components, but that was more because the part was only available in the through-hole package, and not for any reliability advantage.

Sometimes, particularly for larger packages, we have applied an adhesive under the package or an epoxy to the corners. But that was only done when the structural analysis showed it was needed.

None of these applications were for what I would call extreme acceleration environments, such as a cannon-launched shell (a smart munition). But they do have to survive launch and stage separation pyrotechnical shock, and many thousands of temperature swings.

Finally, many components are just not available in through hole packages. In those cases ways are found to make them work in the given environment.

Leaded parts are always preferred where large number of temp excursions are involved. Even though it was SMT, because of the fine lead pitch, it could not be solder automatically and required a trained operator to hand solder it down.

Read More: Industrial Electronics PCB

#PCB Assembly

Picture of Oliver Smith

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.
Picture of Oliver Smith

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.

What Others Are Asking

Can I make a PCB without a ground plane?

Recently we are developing a portable device which should be very tiny and light. In terms of PCB design, I am thinking whether it is a good idea to exclude ground plane to minimize the product size.

Why are there no BGA chips with triangular tessellation of circular pads?

A triangular tiling would allow π⁄√12 or 90.69% of the footprint to be reserved for the solder balls and the surrounding clearance, while the ubiquitous square tiling only allows π/4 or 78.54% of the footprint to be used. Why are there no BGA chips with triangular tessellation?

Read Detailed Advice From Blog Articles

A Step-by-Step Guide to PCBA Manufacturing
Will Li

PCBA Manufacturing: A Step-by-Step Guide

What Is PCBA Manufacturing? PCBA manufacturing, short for printed circuit board assembly manufacturing, encompasses the intricate process of meticulously placing electronic components onto a printed

Scroll to Top