How to Improve Thermal Conductivity in Electronics: Practical Guide for Makers and Engineers

Overview: Why thermal conductivity matters

Managing heat is central to reliable electronics. High temperatures reduce component life, affect timing and can cause failures in power supplies, MOSFETs, regulators and LEDs. This guide explains how to improve thermal conductivity in electronics at the board and system level, giving practical techniques, calculations, and South Africa-specific considerations such as local availability and lead times. Use this when designing prototypes, lab projects or industrial control systems.

Key concepts and terms

• Thermal conductivity (k): material property, W/m·K.
• Thermal resistance (Rth): °C/W, how much temperature rise per watt dissipated.
• Conduction vs convection vs radiation: conduction moves heat through solids, convection through fluids (air), radiation via electromagnetic waves.

Common failure modes linked to poor thermal design

• Thermal runaway in semiconductors.
• Reduced LED lumen output and colour shift.
• Brownouts from overheated voltage regulators.

Standards, materials and typical thermal specs

Selecting materials with appropriate thermal conductivity is the first step. Below is a short comparison of materials you will commonly encounter on projects and what to expect from each in terms of thermal conductivity.

Practical components and brands

Communica stocks a wide range of heatsinks, thermal pads, and copper-clad PCB options suitable for student and industrial projects. For browsing related parts, see All Products and explore thermal-friendly enclosures on the Collections.

Selection criteria: choose the right cooling approach

When deciding between passive conduction (heatsinks, thermal pads), active cooling (fans), or PCB-level solutions (thermal vias, copper pours), evaluate power dissipation, allowable temperature rise, space, noise, and local supply/lead times. Account teams and labs can request quotes and VAT invoices for educational purchases; check branch collection options at the Branches & Trading Hours page.

Calculations and worked examples

Use thermal resistance to estimate steady-state temperature rise. Basic formula:

T_j = T_ambient + (P_dissipated × Rth_total)

Where Rth_total is the sum of junction-to-case, case-to-heatsink (or board), and heatsink-to-ambient resistances. Example: a regulator dissipates 2.5 W, ambient 30°C, and Rth_total = 15 °C/W gives T_j = 30 + (2.5 × 15) = 67.5°C.

Thermal vias and copper pours on PCBs

Thermal vias connect top-layer pads to internal or bottom copper to spread heat. Typical design guidance:

• Use multiple vias (e.g., an array of 8-16, 0.3-0.4 mm drill) under power packages.
• Increase copper pour thickness (e.g., 2 oz copper) for large heat spreaders.

Heatsink mounting and interface materials

Maximise contact area and fill microscopic gaps with thermal paste or a thermally conductive pad. Use thin TIM (thermal interface material) for low-profile applications; use silicone pads where electrical isolation is required. Typical TIM values are 1-4 W/m·K for pastes and 3-7 W/m·K for advanced pads-check datasheets for exact numbers.

Practical wiring/placement diagram (ASCII)

A common layout places the heat source near a copper pour and an edge-mounted heatsink with airflow path:

 [Fan] -->  ---> --------- PCB Top --------- 
                 |  IC (heat)  |  Copper pour |  Heatsink (edge)
                 ---------------------------------------------

Troubleshooting and validation

If temperatures are higher than expected, check the following steps:

• Confirm power dissipation calculations and measure actual current/voltage.
• Measure thermal resistance at key interfaces with a thermocouple or IR camera (note emissivity settings).
• Check mounting pressure and TIM application for air gaps or insufficient contact.
• Verify fan airflow direction and whether dust or obstructions reduce convection.

Test setups and tools

Useful lab tools include thermal paste, thermal pads, heatsinks, small fans, thermocouples, and IR thermometers. Communica lists many of these under tool and test categories; search trusted brands on the Shop by Brand page. For general browsing and design parts, use the Homepage.

Local considerations and procurement tips

For South African projects, plan for occasional lead times on specialised copper or large blowers. Use branch pickup at Samrand or Pretoria CBD to avoid shipping delays; branch details are on the Branches & Trading Hours page. For education purchases, request VAT invoices and bulk quotes where available - Communica supports account quotes for tertiary labs and procurement teams.

Summary checklist

• Calculate expected power dissipation and Rth_total before selecting cooling.
• Prefer copper pours and thermal vias for PCB heat spreading.
• Use appropriate TIM and ensure good mechanical contact with heatsinks.
• Consider forced convection for >5 W localized dissipation, passive for low-power designs.
• Plan procurement with local availability and branch pickup in mind.

Sources

• Communica - About Us
• Communica - Collections and product categories
• Engineering Toolbox - Thermal conductivity reference
• Altium - PCB thermal management guidance