After a high-power LED module or a power conversion unit is bolted onto its heat sink, the measured temperature often sits well above the simulated value. In many cases the heat sink area is adequate and the real issue is the thin layer in between: whether the bond is uniform, whether air gaps remain, and whether contact pressure is sustained.
Product Confirmation and Article Value
The Lixing Fiberglass Thermal Conductive Tape (SKU H-GT-WH) uses a fiberglass face stock with a uniform adhesive coating, providing a conduction path and electrical insulation at the same time. The official product page lists a face stock thickness of 0.050 ± 0.003 mm, an adhesive thickness of 0.045 ± 0.003 mm, a total thickness of 0.095 ± 0.005 mm, and a transparent PET release film liner. This article focuses on thermal-interface-contact and shows how those published facts translate into auditable interface decisions.
Three Mechanisms Directly Tied to Interface Contact
To begin with, what remains in the heat path after lamination is the face stock plus the adhesive, 0.095 ± 0.005 mm in total; the liner is peeled away at application and should not be counted. Next, a uniform adhesive layer wets and fills the microscopic valleys of the substrate surface, and ASTM D5470-17 notes that applying a thermal medium to the test surfaces can reduce contact resistance, which is the engineering reason for using a thin tape instead of bare contact. In addition, the fiberglass base provides structural strength and tensile durability suited to automated lamination, which helps keep the bond geometry consistent in continuous production. These points are selection reasoning derived from published data, not undisclosed product test results.
Engineering Formula: The Series Nature of Interface Thermal Impedance
Z_int = R_c1 + (BLT / k) + R_c2. Here Z_int is the total interface thermal impedance (m²·K/W), BLT is the bond line thickness after lamination (m), k is the through-plane thermal conductivity (W/(m·K)), and R_c1 and R_c2 are the contact resistances on the heat-source and heat-sink sides (m²·K/W). According to ASTM D5470-17 Standard Test Method, plotting measured thermal impedance against specimen thickness gives apparent thermal conductivity as the inverse of the slope, and the sum of the contact resistances at the two surfaces as the zero-thickness intercept. The expression applies to steady-state, one-dimensional heat flow with a fixed cross-section, uniform contact pressure and a conductivity treated as constant; it is an engineering model and conceptual explanation, not a specification or guaranteed value for this product. R_c1 and R_c2 depend on surface roughness, flatness and contact pressure on both sides, are not published on the official product page, and should not be assumed to be zero.
Five Technical Highlights
- Thin layer build: 0.050 ± 0.003 mm face stock plus 0.045 ± 0.003 mm adhesive, 0.095 ± 0.005 mm in total.
- Thermal conductivity: the official page lists 0.35 W/(m·℃).
- Electrical insulation: breakdown voltage is listed at 5 KV.
- Adhesion behaviour: annular initial tack 0.5 kg/25mm, adhesion to mirror steel 1.3 kg/25mm, retention 24 H.
- Service temperature: the published range is -20°C to 120°C.
Civil Industrial Applications
The applications listed on the official page cover thermal management and fixing for high-power LED modules and fixtures, bonding of cooling components inside notebooks and tablets, heat dissipation for touch panels and LCD modules, and thermal bonding between power conversion equipment and heat sinks. What these cases share is a need for a conduction path, electrical separation and mechanical fixing between a heat source and a heat sink, within a space that is often a fraction of a millimetre.
Selection and Design Reminders
When evaluating the Fiberglass Thermal Conductive Tape, three checks help: confirm that the heat-path thickness excludes the liner, confirm that the operating temperature stays within -20°C to 120°C, and review the roughness and flatness of the mating surfaces. The 0.35 W/(m·℃) figure is a material conductivity and is not the assembled Z_int; the 1.3 kg/25mm value refers to mirror steel, so adhesion to anodised aluminium or painted surfaces needs confirmation per model and condition. The official page lists no third-party certification or flammability rating, so such requirements should be raised separately.
Conclusion
The value of a thin thermal tape lies less in a single conductivity number and more in whether 0.095 mm of material can deliver bonding, insulation and fixing together while keeping contact resistance on both sides within a repeatable range. If you are working on interface contact for LED modules or power conversion equipment, start from the official product data and plan verification around your actual substrates and duty cycle.
Topic tags: fiberglass thermal conductive tape, thermal interface contact, contact resistance, thermal interface material, LED cooling, power module cooling
