THERMAL MANAGEMENT IN RUGGED CABLE ASSEMBLIES: WHAT TO KNOW
Introduction: The Often Overlooked Role of Thermal Design
In rugged electronic systems, performance and reliability are driven by more than just bandwidth and shielding. One critical factor that often determines long-term success is thermal management.
From high-power radar systems to autonomous vehicles, modern platforms generate substantial heat, not just from active electronics but also within passive interconnects such as cable assemblies. If cables are not designed to manage this thermal load, they can degrade prematurely, cause signal loss, or even fail in service.
At Meritec, we understand that thermal performance is a key component of rugged cable assembly design. Our engineering approach integrates material science, electrical performance, and mechanical resilience to ensure that assemblies operate reliably even under extreme thermal conditions. In this article, we’ll explore what engineers need to know about thermal management in cable assemblies and how Meritec addresses these challenges.
Why Thermal Management Matters More in Rugged Systems
In benign environments like office IT installations, thermal loads on cables are typically low. But in rugged aerospace, military, industrial, and transportation systems, assemblies are exposed to:
- Ambient temperatures ranging from -55°C to +125°C (or higher)
- Self-heating from power-carrying conductors
- Proximity to heat-generating equipment such as engines, power converters, or RF amplifiers
- High-density installations with poor airflow
Without proper design, these conditions can lead to insulation breakdown, loss of dielectric properties, accelerated aging of materials, and permanent deformation. Moreover, as data rates increase, cable assemblies must maintain tight impedance control across temperature swings to preserve signal integrity.
Key Thermal Challenges in Rugged Cable Assemblies
1. Material Thermal Limits
Every cable material, whether dielectric, conductor, or outer jacket has a thermal limit where properties begin to degrade. For example, common thermoplastics like PVC may soften at relatively low temperatures, whereas engineered fluoropolymers or cross-linked polyolefins maintain performance up to 200°C or beyond. Meritec carefully selects materials to match both the electrical and thermal demands of each application..
2. Heat Dissipation
Cables carrying high current or exposed to nearby heat sources must be designed to dissipate heat effectively. Factors such as conductor gauge, strand count, and jacket thickness all influence how heat builds up or escapes. Thermal modeling allows engineers to predict cable temperature rise under load and select optimal configurations.
3. Thermal Cycling and Fatigue
Many rugged systems experience frequent thermal cycling, such as daily startup/shutdown sequences in outdoor equipment or altitude-induced changes in aircraft. These cycles cause materials to expand and contract, which can introduce mechanical stress over time. Robust strain relief and fatigue-resistant materials help mitigate long-term damage.
4. Insulation Breakdown and Electrical Safety
Elevated temperatures can lower the dielectric strength of insulation materials, increasing the risk of breakdown or arcing in high-voltage systems. Proper insulation selection, spacing, and quality control are critical in maintaining electrical safety across the operating temperature range.
How Meritec Designs for Thermal Performance
Meritec takes a holistic approach to thermal management, starting with a detailed understanding of the customer’s system environment and thermal profile. Our engineering process includes:
| Design Element | Meritec Approach |
|---|---|
| Material Selection | High-temperature-rated insulation, conductors, and jackets based on system specs |
| Conductor Sizing | Optimized gauge and stranding to balance electrical performance and heat dissipation |
| Shielding and EMI Control | Low-resistance shields that minimize heat buildup from RF currents |
| Strain Relief and Termination | Mechanically robust designs that prevent thermal fatigue at connector interfaces |
| Testing and Validation | Environmental chamber testing for temperature extremes and cycling |
By applying these principles, Meritec ensures that our cable assemblies not only survive but thrive in high-heat environments.
Application Example: Avionics and Aerospace Electronics
An aerospace customer approached Meritec to design a cable assembly for avionics equipment mounted near turbine engines, where ambient temperatures routinely exceeded 100°C. In addition, the cables needed to carry high-frequency RF signals without significant loss.
The solution involved:
- Using PTFE-insulated conductors with a temperature rating of +200°C
- Silver-plated copper shielding for both EMI protection and thermal resilience
- Custom overmolding at the connector ends to prevent mechanical strain from thermal cycling
- Testing under full thermal profile, including exposure to -55°C startup conditions
The result was a cable assembly that maintained signal integrity across the entire flight envelope, with no degradation after extended thermal cycling.
How Thermal Affects Signal Integrity
Beyond basic survivability, thermal effects can significantly impact signal quality in high-speed or precision analog systems. Rising temperatures can:
- Increase conductor resistance, leading to higher insertion loss
- Alter dielectric constant, shifting impedance and introducing reflections
- Cause drift in differential skew, which affects timing alignment in digital systems
This is why Meritec’s thermal-aware designs go beyond simple “heat survival.” We ensure that assemblies maintain impedance, low skew, and consistent signal integrity across the temperature extremes of each application.
Meritec’s Capabilities in Thermal-Optimized Assemblies
Meritec offers:
- Cable assemblies rated for -55°C to +200°C operating ranges
- Advanced dielectric materials for signal integrity at high temperatures
- Custom conductor configurations for power and signal
- Rugged connector overmolding and strain relief to handle thermal cycling
- Full thermal validation including temperature, humidity, and cycling
We serve aerospace, defense, industrial automation, EV power electronics, rail, and more, wherever heat is a system challenge.
Partner with Meritec to Solve Thermal Challenges
Thermal management is no longer optional in rugged system design. If your application faces temperature extremes, heat-generating components, or high-power loads, Meritec can engineer cable assemblies that rise to the challenge.
Our team is ready to collaborate, bringing deep materials expertise, practical design experience, and proven solutions for thermal performance.
Explore rugged cable solutions: https://www.meritec.com
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