Softtherm Gap Filler Pads - MH&W International Corp.

Kerafol^®

Softtherm^® Gap Filler Pads

As the push for higher power densities and smaller device footprints creates significant air gaps between components and heat sinks, robust thermal management is critical to maintain system stability. To bridge these varying distances, Kerafol^® offers the Softtherm^® range of gap filler pads, providing ultra-soft and highly compressible interface solutions that effectively displace air in large cavities. These specialized pads deliver a versatile, low-stress method for conducting heat in complex assemblies where standard thin films cannot reach or conform to irregular surface geometries.

Bridging Large Vertical Gaps

While standard films are typically limited to 0.5 mm, Softtherm^® pads are available in thicknesses up to 5.0 mm. This allows them to bridge significant air voids between hot components and the chassis or heat sink that thin films simply cannot reach.

Multi-Height Components

A single large gap filler pad can cover an entire PCB section, cooling multiple components of varying heights simultaneously. This greatly simplifies assembly compared to applying individual thin films to every component.

Long-Term Interface Stability

Unlike thermal greases or lower-end materials that can dry out, “pump out,” or crack over time, Keratherm gap pads are fully cross-linked elastomers. They maintain their elastic “memory” and consistent thermal performance over years of continuous use in harsh environments.

Elimination of Secondary Adhesives

Many Softtherm^® variants are naturally tacky or available with specialized adhesive coatings. This “self-adhesive” property allows for easy pre-assembly on heat sinks—even in vertical or upside-down orientations—without needing additional tapes that would increase thermal resistance.

High Dielectric Protection

Because these pads are significantly thicker than standard films, they provide a much more robust electrical insulation barrier. This makes them ideal for high-voltage applications where a thin film might be susceptible to “cut-through” from sharp component edges or PCB burrs.

Ease of Rework & Maintenance

Unlike permanent thermal glues or messy pastes, gap filler pads allow for clean and easy removal. If a board requires testing or a component needs replacing, the pad can be removed without leaving significant residue, ensuring a fast and non-destructive rework process.

Why should i use Gap Filler Pads?

Superior Conformability: Unlike thinner standard films, gap filler pads are soft and highly compressible, allowing them to mold into irregular surface topographies and fill large air gaps between components of varying heights.

Stress Reduction: The low-modulus nature of these pads applies minimal pressure to sensitive components during assembly, preventing mechanical stress or board bowing while maintaining excellent thermal contact.

Tolerance Compensation: These pads are ideal for applications with high mechanical tolerances, as they can compress significantly to take up space where a standard film would leave a performance-robbing air pocket.

Vibration Dampening: Due to their thicker, more compliant structure, gap filler pads provide enhanced vibration and shock absorption, protecting delicate solder joints and internal connections in rugged industrial or automotive environments.

Who is Kerafol^®?

A family-run specialist in thermal management and technical ceramics, KERAFOL^® leverages decades of expertise to develop high-performance, sustainable solutions for future technologies. Through state-of-the-art manufacturing and dedicated consulting, they provide customized, “cool” electronics support across the mobility and industrial sectors.

Softtherm^® Comparison Chart

Film	Thermal Conductivity (W/mK)	Thermal Resistance (K/W)	Breakdown Voltage (kV)	Measured Thickness (mm)	Hardness (Shore 00)	Possible Thicknesses (mm)	Characteristics	Datasheet	View Product
86/200	1.0	1.20	8.0	0.5	10-20	0.5 - 5.0	Super Soft Material. Double Layer with Good Insulation.	PDF	VIEW
86/125	1.5	0.80	6.0	0.5	10-25	0.5 - 5.0	Fiberglass Reinforcement. Extra Soft Material..	PDF	VIEW
86/225	2.0	0.60	6.0	0.5	30-45	0.5 - 5.0	Fiberglass up to 4.0mm. Soft Material. Good Insulation.	PDF	VIEW
86/228	2.0	0.60	6.0	0.5	30-45	0.5 - 3.0	Soft Double Layer Material with Good Insulation.	PDF	VIEW
86/235	2.0	0.60	6.0	0.5	25-40	0.5 - 5.0	Low Bleeding. Fiberglass up to 2.0mm. Good Insulation.	PDF	VIEW
86/238	2.0	0.60	6.0	0.5	25-40	0.5 - 3.0	Soft Double Layer Pad with Low Bleeding & Good Insulation.	PDF	VIEW
U110	2.0	1.20	8.0	0.5	60-75	0.5 - 3.0	Silicone Free. Elastic with Good Aging Behavior & Low Hardness.	PDF	VIEW
86/320	2.5	0.50	5.0	0.5	25-38	1.0 - 5.0	Soft Material with Fiberglass up to 1.5mm. High Elastic Properties.	PDF	VIEW
86/325	3.0	0.41	6.0	0.5	35-50	0.5 - 4.0	Soft Material. Good Properties. Fiberglass up to 1.0mm.	PDF	VIEW
3500	3.5	0.36	5.0	0.5	45-65	0.5 - 4.0	Soft Material with Good Elastic Behavior. and Properties..	PDF	VIEW
86/450	4.5	0.27	5.0	0.5	65-75	0.5 - 4.0	Great Price Performance Single Layer, No Fiberglass.	PDF	VIEW
86/525	5.5	0.44	1.25	0.5	50-65	0.5 - 3.0	Adhesive Available. No Fiberglass. Single Layer..	PDF	VIEW
6000	6.0	0.41	4.0	0.5	55-75	0.8 - 3.0	Excellent Thermal Properties. Elastic and Low Hardness..	PDF	VIEW

Frequently Asked Questions

How much should I compress a Softtherm^® pad for optimal performance?

At maximum pressure, pads should not be compressed beyond 30% of their original thickness. Exceeding this limit may cause the material to “leak out” or apply excessive mechanical stress to components.

What thickness range is available for these Softtherm^® Gap Filler Pads?

Unlike standard thin films, Softttherm^® Gap Filler Pads are available in a wide variety of thicknesses ranging from 0.5 mm up to 5.0 mm. This allows them to bridge significant air voids in large cavities that films cannot reach.

Do these pads require a separate adhesive for mounting?

No, most Softtherm^® pads possess a natural inherent tack that facilitates easy pre-assembly on components. For vertical or “upside-down” applications requiring a stronger bond, optional single-sided adhesive coatings are available.

Can the pads be reused or repositioned during assembly?

Yes, depending on the surface and the specific material, these pads can often be repositioned during assembly. Their fully cross-linked elastomeric structure allows for cleaner removal than pastes or glues, though reuse should be verified by a design engineer.

Will the hardness of the pad change at extreme temperatures?

For silicone-based Softtherm^® materials, there is no significant variance in hardness within the standard application temperature range of -60°C to +200°C. This ensures consistent mechanical and thermal performance throughout the device’s lifespan.

As thermal demands rise with miniaturization, MH&W’s Thermal Division provides the expertise and Keratherm^® materials necessary to prevent system failure. Contact our engineers for technical support, request an RFQ, or purchase standard sheets directly from our online shop.

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