ESCATEC Blog

What is ruggedisation in electronics design?

Written by Neil Sharp | 10 Sep, 2024

In the last twenty years electronics have become embedded in all kinds of industrial equipment from factory lines to fish farms, construction machinery to combine harvesters. These machines must operate in the harshest conditions over long periods of time. So, how can we ‘ruggedise’ their design to maximise lifespan and performance?

What is ruggedisation in electronics design?

Ruggedisation refers to the process of designing and manufacturing devices to withstand harsh environmental conditions and operate reliably in the most challenging settings.

What devices need to be ruggedised?

Sectors and machinery that require ruggedisation support include:

What are the goals of ruggedisation?

Ruggedisation aims to make equipment more robust and usable in extreme conditions, while ensuring that the sensitive electronics inside remain safe from damage.

Ruggedisation protects equipment and electronic systems from the effects of:

  • Extreme temperatures (both high and low)
  • Moisture, humidity, and water exposure
  • Dust and particulates
  • Shock and vibration
  • Electromagnetic interference (EMI)
  • Explosive gases

It also aims to enhance durability and reliability:

  • Extend device lifespan in harsh conditions
  • Reduce failure rates and maintenance needs
  • Ensure consistent performance under stress

What standards can apply in ruggedised product design and testing?

Standards such as IP (Ingress Protection) ratings (for water resistance) and MIL-STD-810  (a standard for building military-grade equipment) can help define required resistance to dust, water, shock, and extreme temperatures. 

Working against these standards in design and testing can guarantee that equipment is able to withstand the rigours of the most demanding environments, enhancing operational efficiency and longevity.

What are the key steps for the design and manufacture of ruggedised devices?

 

Environmental assessment

From the earliest part of the design process consider all the specific environmental use cases for your design. Specify the stresses the devices and their operators will likely be exposed to in each scenario and the potential risk to its performance and usability as a result.

For example, with agricultural or construction machinery used outdoors and in all weathers, there can be various environmental risks to its effective mechanical and electronic operation, as well as threats to user-safety. These might include:

  • Frozen mechanics
  • Slippery/ungrippable controls
  • Cracked dashboards
  • Overheated/frozen components
  • Flooded enclosures
  • Damage through excessive vibration
  • Electronic corrosion due to damp or oxidising gases

As you build your designs you need to consider how the whole device will work together to create the right level of ruggedisation - meeting all your usability, connectivity, lifespan and maintenance expectations. Here are some of the most significant considerations that should govern a rugged product design.

Material selection

Choosing the right materials for components is fundamental to maintaining consistent performance in specified conditions over time. Ensuring you have the right support in balancing required durability with ingress protection, weight, ventilation and connectivity requires input from all kinds of design, manufacturing and procurement specialists.  

Electronics design

When it comes to electronics a whole range of considerations and approaches should govern how you ruggedise your electronics and enclosure designs.

Environmental challenge

Design approach

High temperatures

  • Use conduction cooling (chassis/heat sink)
  • Apply thermal interface materials
  • Implement active cooling with fans
  • Spread out hot components on PCB
  • Use ceramics or metal-core PCBs
  • Consider liquid cooling for extreme cases
  • Select high-temperature rated components
  • Implement thermal shutdown protection circuits

Low temperatures

  • Use ingress protection to prevent condensation
  • Apply DC heating to maintain normal operating range
  • Select components rated for low-temperature operation
  • Use materials with low thermal expansion coefficients
  • Implement temperature compensation circuits

Extreme thermal cycling

  • Use high Tg (glass transition temperature) laminates
  • Avoid stacked vias
  • Implement stress-relief in component mounting
  • Use flexible PCB materials where appropriate
  • Perform thermal simulation and testing

High pressure environments

  • Design for extreme temperatures
  • Select components that will not implode
  • Use conformal coating
  • Fill enclosure with inert gas or insulating liquid
  • Implement pressure equalization systems
  • Use reinforced enclosures

Mechanical vibration or shock

  • Use through-hole components where possible
  • Design board to ensure lowest order resonant frequency is at least triple the expected shock frequency
  • Solder large ICs directly to the board
  • Use staking compounds or underfill for components
  • Implement shock mounting for PCBs
  • Use vibration dampening materials

Electrical discharge

  • Keep earth ground close to chassis and TVS grounds
  • Use ESD protection circuits
  • Implement proper shielding
  • Use ESD-resistant materials for enclosures
  • Design PCB layout to minimize ESD susceptibility

Particulates

  • Use conformal coatings to prevent ESD
  • Design high pressure sealed enclosures
  • Implement filtration systems for air intake
  • Use positive pressure inside enclosures
  • Select connectors with appropriate IP ratings

Corrosion from moisture or oxidizing gases

  • Use conformal coatings with appropriate chemistry
  • Design sealed enclosures with high pressure ratings
  • Select corrosion-resistant materials
  • Implement moisture barriers
  • Use desiccants inside enclosures

Explosive gases

  • Eliminate components that could create sparks (e.g., relays)
  • Apply ESD protection measures
  • Implement gas detection and shutdown systems
  • Use explosion-proof enclosures

 

Mechanical design

Your products should also be designed with robust, mechanical operation in mind.

Attention to moving parts: Hinges, plugs, actuators, and other moving parts require special attention in rugged designs.

Temperature and wear considerations: Account for interactions as parts undergo temperature changes, wear, and potential misuse.

Serviceability: Design parts to be easily replaceable and ensure preventative maintenance is straightforward to enable regular upkeep.

Self-cleaning mechanisms: Implement designs that allow components to self-clean during system cycles to prevent dirt and grime build-up.

Testing and validation

When you are building your rugged products, ensure you devise the right testing process to validate your designs and deliverables.

Conduct rigorous testing: Perform environmental testing, including temperature cycling, humidity tests, vibration tests, and shock tests, to validate the device's durability and reliability.

Iterate and improve: Identify weaknesses through testing and make necessary improvements before finalising the design.

Innovators should take a holistic approach to ruggedised mechatronic design, ensuring every element of your end-product can work seamlessly together, and be maintained effectively over time. 

Rugged designs require collaboration with a range of specialists

Working with design and manufacturing partners early on in the development process will ensure that your rugged product can be realised in the most efficient and cost-effective way possible. It will ensure that electronics are designed and manufactured to be effectively protected and serviced appropriately over time.

Early collaboration helps identify potential challenges, optimise material selection, and streamline the integration of protective measures such as sealing, shock absorption, and thermal management. This proactive approach reduces the risk of costly redesigns, accelerates time-to-market, and enhances the overall quality and performance of the final product.