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Compare thermal paste and thermal pads: performance, installation, calculations and SA-specific buying tips for makers, students and technicians.
Paste usually offers better thermal transfer; pads are cleaner and easier to use.
Use pads for larger, inconsistent gaps; paste for tight, high-power interfaces.
Check local stock, VAT invoices and branch pickup options at Communica.
Thermal interface materials (TIMs) such as thermal paste and thermal pads bridge microscopic gaps between a heat source (CPU, GPU, power regulator) and a heatsink or enclosure. Choosing the right TIM affects operating temperature, throttling behaviour and component longevity. This guide compares thermal paste vs pad comparison across thermal performance, ease of use, reworkability and SA-specific considerations like local availability and lead times.
Thermal paste (grease) generally offers lower thermal resistance and better microscopic surface wetting, while thermal pads provide cleaner installation, predictable thickness and electrical insulation options. The right choice depends on thermal load, serviceability and mechanical gap variations.
Key properties to compare are thermal conductivity (W/m·K), thermal resistance (Rth, K/W), layer thickness (mm) and operating temperature range. For a simple steady-state heat conduction estimate across a TIM layer you can use Fourier's law in one dimension:
Q = k * A * (DeltaT) / d
Rearranged for temperature rise across the TIM: DeltaT = Q * d / (k * A), where Q is heat power (W), d is thickness (m), A is contact area (m2) and k is thermal conductivity (W/m·K). Use this to estimate the added temperature drop across the interface for your project.
If a Raspberry Pi hat dissipates 3 W over an area of 20 x 20 mm (A = 0.0004 m2) and you use a thermal pad with k = 4 W/m·K and thickness d = 1 mm (0.001 m):
DeltaT = 3 * 0.001 / (4 * 0.0004) = 1.875 K. A low-viscosity thermal paste with effective k = 8 W/m·K at a thinner effective thickness of 0.1 mm would give DeltaT = 3 * 0.0001 / (8 * 0.0004) = 0.09375 K, showing how paste can reduce the interface temperature in tight clearances.
These figures are estimates; actual performance depends on surface flatness, mounting pressure and how well the TIM fills micro-gaps. In South Africa, ambient temperatures and cooling strategies (passive vs active) should factor into your thermal design.
| Property | Thermal Paste | Thermal Pad |
|---|---|---|
| Typical thermal conductivity | 1-12 W/m·K (varies by compound) | 1-8 W/m·K (higher-grade pads up to ~12 W/m·K) |
| Thickness control | User-applied, thin & variable | Pre-defined thickness (0.5-5 mm common) |
| Ease of installation | Moderate - requires cleaning and correct amount | Easy - peel-and-stick, cleaner for beginners |
| Reworkability | Good - can be cleaned and reapplied | Depends - some pads compress permanently |
| Electrical insulation | Some pastes are electrically conductive - check datasheet | Many pads are electrically insulating options available |
Tip: when in doubt for high-power CPUs or GPUs, choose a high-conductivity paste and ensure even mounting pressure. For quick repairs, prototyping or when gaps are inconsistent, a pad can save time and reduce mess.
For product browsing and part selection see the Communica collections for heatsinks, adhesives and thermal supplies at communica.co.za/collections and the full product index at communica.co.za/collections/all.
Use the following checklist to choose the optimal TIM for your South African project.
High continuous power (desktop CPU/GPU, power resistors) benefits from low Rth paste. For low-power boards or intermittent loads, a pad often provides adequate performance with simpler installation.
If heatsink-to-component gap varies or you need 1-3 mm thickness, thermal pads offer predictable filling. For tight, well-mounted interfaces, paste is almost always the better conductor.
For classroom or maker-lab environments where parts are frequently removed, pads reduce mess and speed up swaps. For student labs demonstrating thermal conductivity and calculations, paste provides a more realistic engineering outcome.
Use a thin thermal pad (0.5-1 mm) when mounting a small aluminium heat spreader to a Pi case, especially if the board has components with slightly different heights. Pads avoid spilled paste on GPIO headers and simplify classroom setups.
Select a mid-to-high conductivity paste and follow manufacturer torque/mounting sequence for the cooler. Clean old paste with isopropyl alcohol before reapplication. For overclocking or sustained heavy loads, re-apply quality paste every 2-3 years (estimates depend on compound and environment).
For local availability, branch collection and quoting for educational or bulk purchases, check Communica's branch details and trading hours at Branches & Trading Hours. Communica stocks a wide selection of maker and engineering supplies; browse brands and components at Shop by Brand and the company background at About Us.
When sourcing TIMs in South Africa, allow for potential lead times on specialised high-conductivity pads or niche pastes. For education and prototyping, order small packs or sample kits first. For procurement teams, request VAT invoices and stock checks from the Samrand warehouse to plan budgets in ZAR. Typical small-container pastes in the local market may range from under ZAR 50 for basic tubes to several hundred ZAR for premium syringes or kits; these are indicative ranges and subject to supplier pricing and availability.
Choose thermal paste when thermal performance is the priority and you can control mounting pressure and cleanliness. Choose thermal pads for simplicity, predictable thickness or when electrical insulation is required. For many maker and education projects, keeping both on hand covers most scenarios.
Communica supplies semiconductors and electronic components to industries such as automotive, electrical, automation, mining, and education.
Disclaimer: This content is for educational purposes only. Product availability, pricing, and specifications are subject to change. Always verify current details on the retailer's website before making a purchase. We may earn affiliate commissions from qualifying purchases.
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