Gap Filler Liquids

As electronic components become more compact and complex, MH&W offers Keratherm^® Gap Filler Liquids as a high-performance alternative to traditional pads. These two-part, thermally conductive materials flow effortlessly into irregular geometries and intricate gaps, ensuring total surface contact and superior heat transfer. By providing excellent electrical insulation and low-stress application, Keratherm^® liquids protect fragile assemblies while supporting high-volume, automated dispensing for a more efficient and reliable manufacturing process.

Superior Surface Coverage

These two-part liquids flow into the most complex geometries and irregular gaps, ensuring total surface contact where solid pads cannot reach.

High Thermal Performance

Engineered with specialized ceramic fillers, these liquids maximize heat dissipation to significantly lower operating temperatures for high-power components.

Stress-Free Assembly

The low-viscosity application applies minimal pressure to delicate circuit boards, preventing mechanical strain on fragile solder joints and sensitive components.

Exceptional Electrical Insulation

Formulated to provide high dielectric strength, these liquids ensure components remain electrically isolated while transferring heat to prevent short circuits.

Long-Term Reliability

Unlike thermal greases, these liquids cure into a stable form that will not pump out, dry out, or migrate over time, maintaining consistent performance for the device’s lifespan.

Optimized for Automation

Designed specifically for high-volume robotic dispensing, these liquids reduce labor costs and streamline manufacturing through precise, automated application.

Why should i use Gap Filler Liquids?

Tolerance Compensation: These liquids easily bridge varying gap heights and component tolerances within a single application, eliminating the need to stock multiple pad thicknesses for different areas of a PCB.

Vibration and Shock Dampening: Once cured, the elastic properties of the gap filler provide a cushioned interface that absorbs mechanical vibrations and protects internal components from physical shock in harsh environments.

Reduced Material Waste: Unlike die-cut films that leave scrap material behind, liquid dispensing is a “zero-waste” process that applies only the exact amount of material required for each specific component.

Enhanced Component Wet-Out: The liquid’s ability to “wet” the surface at a microscopic level eliminates trapped air pockets more effectively than solid materials, significantly reducing overall thermal interface resistance.

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.

Gap Filler Liquid Comparison

Product	Viscosity (Pas)	Curing (h@RT)	Thermal Cond. (W/mK)	Thermal Res. (K/W)	Breakdown Volt. (kV)	Dielectric (kV/mm)	Measured Thick. (mm)	Hardness (Shore 00)	App. Temp (°C)	Density (g/cm³)	Datasheet
GFL 3020	45 - 70	1	1.8	0.7	10.0	20.0	0.5	45 - 60	-40 to +200	2.3	PDF
GFL 3025	45 - 75	1	2.5	0.5	8.0	16.0	0.5	65 - 85	-40 to +200	2.83	PDF
GFL 3030	50 - 80	1	3.0	0.41	6.0	12.0	0.5	65 - 85	-40 to +200	2.94	PDF
GFL 3040	75 - 110	1	4.0	0.29	5.0	10.0	0.5	65 - 85	-40 to +200	3.05	PDF
GFL 1800 SL	2 - 7	1	1.8	0.69	7.5	15.0	0.5	55 - 75	-40 to +200	2.3	PDF
GFL 3000 SL	10 - 30	1	2.8	0.9	6	12.0	0.5	55 - 75	-40 to +200	2.77	PDF
GFU 15 Silicone Free	A/B: 140-160	<24	1.5	0.8	8	16.0	0.5	65 - 85	-40 to +80	2.3	PDF

Frequently Asked Questions

What exactly are Keratherm^® Gap Filler Liquids compared to standard thermal grease?

While both substances fill the microscopic air gaps between a component and a heatsink, Keratherm^® Gap Filler Liquids are essentially liquid gap pads. Thermal grease stays as a wet paste, which can eventually pump out or dry up under heat cycles. These liquids, however, are dispensed as a fluid but cure into a soft, stable elastomer. This gives you the perfect wetting of a liquid with the long-term mechanical stability of a solid pad.

Is it safe to use these on fragile or sensitive electronic components?

These materials are actually ideal for delicate setups. Because they are applied in a liquid state, they require almost zero assembly pressure to spread across a surface. This eliminates the mechanical stress often caused by squeezing a firm thermal pad onto a board, which protects fragile solder joints and sensitive surface-mount devices from cracking during the manufacturing process.

What kind of equipment is required for the application process?

The setup depends entirely on the volume of your project. For prototyping or small-scale repairs, the material is usually available in dual cartridges that work with a simple manual dispensing gun and a static mixing nozzle. For high-volume industrial manufacturing, these liquids are designed for automated dispense-in-place systems that provide high-speed, high-precision application directly onto the production line.

How does the curing process work and how long does it take?

Most Keratherm^® Gap Fillers are two-component systems that begin to react once they pass through the mixing nozzle. They typically cure at room temperature, though the process can be sped up significantly by applying heat in a curing oven. Once the chemical reaction is complete, the material becomes a vibration-resistant solid that will not leak or migrate, even if the device is mounted vertically or subjected to heavy motion.

What are the key technical specs to consider when choosing a version?

You should primarily focus on thermal conductivity, which is measured in W/mK. A higher number indicates more efficient heat transfer. Additionally, consider the viscosity, which dictates how easily the liquid flows into complex gaps, and the final Shore hardness. The Shore hardness tells you how soft the material remains after curing, which is vital if your design relies on the gap filler to absorb mechanical vibrations.

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.