In power supplies and PCB assemblies, heat often stalls in the thin, uneven gaps between components and the metal enclosure. A silicone thermal gap pad bridges that gap into one continuous heat path: the product page lists grades from 1.0 to 10.0 W/m·K and an ultra-soft 5 to 40 Shore B hardness, so the pad compresses under low pressure, conforms to uneven surfaces, and carries heat from the component into the heat sink or metal chassis.

Benefit 1: Heat Gets a Path Instead of an Air Gap

When two rigid surfaces are pressed together, they touch only at a few high points; the rest is a thin layer of trapped air, and gases conduct heat poorly. A gap pad fills that layer. The product page describes it filling micro air gaps between heat-generating components and cooling modules and conforming to uneven surfaces to reduce interface thermal resistance. Remove the air from the path and the temperature drop has room to shrink.

Benefit 2: 1.0 to 10.0 W/m·K Grades Matched to Each Heat Load

Not every segment of a heat path needs the same grade. The product page offers multiple grades from 1.0 to 10.0 W/m·K, selected by grade, so a low-power position and a power device pressed against a heat sink can be evaluated separately, putting the budget where heat is actually blocked.

Benefit 3: 5 to 40 Shore B Softness Conforms Under Low Clamping Force

PCBs and plastic housings cannot take heavy screw torque. The listed hardness of 5 to 40 Shore B allows high compression under low pressure, and the material also cushions, absorbing mechanical vibration and protecting fragile components. For how the pad handles interface contact, see our thermal gap pad interface contact guide.

Benefit 4: A Heat Path That Is Also an Insulated Path

The pad often sits between live components and a grounded metal enclosure. The product page lists a UL 94 V-0 / V-1 flame rating, electrical insulation, and a temperature range of -40°C to 200°C. UL 94 is a material flammability classification, not an end-product safety approval; confirm the required withstand voltage and creepage design with us for the specific grade.

Benefit 5: Cut to the Shape of Your Heat Path

Heat paths are rarely a standard square. The product page offers precision die-cutting to customer drawings or roll supply, with color, size, shape, thickness, and surface tack adjustable to the application, so one pad covers the heat source without taking extra space.

Where It Fits

Listed applications include power supplies and high-power LED lighting, CPU and GPU cooling, the interface between thermal modules and metal chassis or housings, 5G telecom equipment, and automotive power components. Each has a distance between heat source and heat sink that needs to be bridged.

Engineering Note: Find the Bottleneck with Series Thermal Resistance

Treat the heat path like resistors in series. A one-dimensional steady-state model is ΔT = Q × (1/(h_c1 × A) + L/(k × A) + 1/(h_c2 × A)). ΔT is the temperature difference from heat-source surface to heat-sink surface (K); Q is the heat flow through the path (W); h_c1 and h_c2 are the interfacial conductances at the two pad contact faces (W/m²·K); L is the compressed pad thickness (m); k is the pad thermal conductivity (W/m·K); A is the effective contact area (m²). The three resistances add, and the largest term sets the temperature drop: if contact is poor, fix conformity first; if the pad body dominates, consider a thinner compressed thickness or a higher grade. Source: MIT A Heat Transfer Textbook, Section 2.3 on thermal and contact resistance.

The model assumes heat flows normal to a uniform slab with equal area in each segment, and ignores spreading, lateral conduction, convection, and radiation. h_c changes with surface finish, pressure, and interstitial medium and must be measured. It is an estimating tool, not a product specification or guarantee. When comparing conductivity grades, also align the test method, since ASTM D5470 steady-state results and laser flash results are obtained under different conditions.

Ready to Connect Your Heat Path?

Send us the heat-source power, the component-to-heat-sink gap, the allowable clamping force, insulation and flame requirements, and a dimensional drawing, and we will help evaluate a suitable grade and shape. Review the thermal gap pad grades and specification table, then email yw@zh-lx.com to request samples or a specification consultation.

#ThermalPad #ThermalManagement #HeatPathDesign #PowerElectronics #PCBCooling