THERM-A-GAP GEL 40NS: Non-Silicone Thermal Gel for Data Center Applications

Understanding THERM-A-GAP GEL 40NS for Data Center Thermal Management

THERM-A-GAP GEL 40NS is a single-component, urethane-based dispensable thermal gel delivering 4.0 W/m-K thermal conductivity for data center applications. The non-silicone formulation eliminates contamination concerns in optical transceivers and sensitive electronics while maintaining thermal performance comparable to silicone alternatives.

Data centers face escalating thermal challenges. AI workloads, cloud computing expansion, and edge infrastructure push processor power densities beyond traditional cooling capacity. CPUs and GPUs now generate heat loads demanding precision thermal interface materials capable of transferring energy efficiently to liquid cold plates and air-cooled heatsinks.

This material guide explains when THERM-A-GAP GEL 40NS provides the optimal solution for data center thermal management — from server processors to solid-state drives to optical transceivers. Engineers seeking lower thermal conductivity options may also consider THERM-A-GAP GEL 30 for data center thermal management applications where 3.0 W/m-K performance meets design requirements.

Essential Background Reading:

• Thermal Interface Materials Selection Guide: Foundational principles for choosing TIMs based on application requirements
• Complete Engineer's Guide to Thermal Management: Comprehensive overview of thermal management concepts and solutions
• Understanding Thermal Contact Resistance: How interface resistance affects heat transfer performance
• Parker Chomerics Thermal Material Guide: Overview of the complete Chomerics thermal interface product portfolio

Why Non-Silicone Matters in Data Center Design

The "NS" designation in GEL 40NS indicates non-silicone formulation — a critical distinction for data center applications where optical systems and sensitive electronics operate continuously. Silicone-based thermal materials release low molecular weight siloxanes that contaminate precision optical surfaces and electrical contacts over time.

Optical transceivers represent the primary concern. High-speed optical components use precision surfaces that silicone outgassing degrades across thousands of operating hours. Data centers handling increasing optical interconnect volumes benefit from non-silicone thermal solutions throughout their infrastructure. Understanding thermal management principles in optical coatings and sensitive systems provides valuable context for material selection in these applications.

Server power supplies and certain semiconductor packages specify non-silicone materials due to surface contamination affecting electrical contacts. The urethane-based binder in THERM-A-GAP GEL 40NS eliminates these compatibility concerns while delivering thermal performance matching silicone alternatives.

Thermal Gel Technology Fundamentals

Thermal gels occupy the middle ground between traditional thermal pastes and solid gap pads. These materials combine liquid conformability with cured compound stability, creating interfaces maintaining consistent thermal performance without pump-out or dry-out across years of continuous operation.

The gel form factor offers distinct manufacturing advantages. Unlike thermal greases migrating under thermal cycling or vibration, properly formulated gels remain dimensionally stable throughout service life. This stability proves critical in data center environments where servers operate continuously between maintenance intervals.

THERM-A-GAP GEL 40NS achieves this stability through urethane-based chemistry. The material arrives fully cured and ready to dispense — no mixing ratios to manage, no pot life concerns, and no secondary curing steps during assembly.

Technical Specifications and Performance Data

The following specifications guide material selection for data center thermal management applications:

The 4.0 W/m-K thermal conductivity positions THERM-A-GAP GEL 40NS in the high-performance category for dispensable thermal interface materials. This performance level supports effective heat transfer from processors, memory modules, and power management components to their respective cooling solutions. For applications requiring even higher thermal conductivity, THERM-A-GAP PAD 80 delivers 8.0 W/m-K performance in a solid pad format.

Related Content:

• Thermal Pads vs. Thermal Form-in-Place: Comparing solid and dispensed thermal interface technologies
• Thermal Gap Pad Compression Optimization: Engineering compression force and bondline for optimal thermal performance
• Advanced Thermal Gel Dispensing Capabilities: Manufacturing processes for precision thermal gel application
• Phase Change Materials for Thermal Management: Alternative TIM technology for demanding applications
• Understanding Outgassing: Why material outgassing matters for optical and electronic systems

Data Center Application Areas

Thermal management extends throughout data center infrastructure, from processors to network switches to power distribution equipment. THERM-A-GAP GEL 40NS addresses multiple application areas.

• Server processors and accelerators: The primary thermal interface between CPUs, GPUs, and their cooling solutions represents the highest-stakes application. The gel accommodates die height variation across processor packages while maintaining consistent thermal contact.
• Memory modules: High-bandwidth memory generates substantial heat in AI and high-performance computing servers. Thermal gels interface memory stacks with spreaders or direct liquid cooling solutions.
• Solid-state drives: Enterprise SSDs require thermal management to maintain performance and longevity. The thin bondline capability suits tight M.2 and U.2 drive form factors.
• Optical transceivers: High-speed optical modules generate heat transferring efficiently to enclosure surfaces. The non-silicone formulation makes THERM-A-GAP GEL 40NS particularly suitable for these optical-sensitive applications.
• Power electronics: Voltage regulators, power supplies, and battery backup systems benefit from effective thermal interface materials maintaining efficiency and reliability. Engineers working with high-temperature power electronics applications face similar thermal management challenges requiring careful material selection.

Design Considerations for Dispensed Gel Applications

Successful dispensed thermal gel implementation requires attention to several design and process parameters. The assembly must provide adequate compression achieving target bondline thickness while avoiding excessive force damaging components.

THERM-A-GAP GEL 40NS requires very low compression force to deform — a characteristic protecting solder joints, component leads, and delicate die structures from mechanical stress. This property proves particularly valuable interfacing with ball grid array (BGA) packages or fine-pitch semiconductor assemblies.

Bondline thickness directly affects thermal resistance. Thinner bondlines reduce thermal resistance, but practical limits exist based on surface flatness and assembly tolerances. The 0.15 mm (0.006") minimum bondline specification provides guidance for design optimization.

Consider these factors when designing thermal gel interfaces:

• Surface flatness: Variations in component and heatsink flatness determine minimum practical bondline thickness
• Gap tolerance stack-up: Account for cumulative tolerance of all components in the thermal path
• Compression hardware: Specify spring-loaded mounting systems maintaining consistent pressure across operating temperature range
• Dispense pattern: Design patterns providing complete coverage without excessive squeeze-out

Manufacturing and Assembly Integration

The dispensable nature of THERM-A-GAP GEL 40NS supports integration into automated assembly processes — critical for high-volume data center manufacturing. The material dispenses consistently across multiple packaging formats, from manual syringes for prototype work to bulk cartridges for production lines.

The following packaging options accommodate different production scales:

Flow rate consistency enables precise dispense programming. Under standard conditions of 621 kPa (90 psi) through a 4.3 mm (0.170") orifice, THERM-A-GAP GEL 40NS delivers 15-25 g/min — predictable enough for automated systems achieving repeatable deposit volumes.

Reliability and Long-Term Performance

Data center equipment operates continuously in demanding environments. Thermal interface materials must maintain performance across years of thermal cycling, vibration, and environmental exposure without degradation.

The fully-cured nature of THERM-A-GAP GEL 40NS eliminates pump-out concerns affecting liquid thermal compounds under thermal cycling. The material remains where dispensed, maintaining consistent thermal contact throughout equipment service life.

Temperature capability from -50°C to 125°C (-58°F to 257°F) exceeds the operating envelope of most data center equipment with substantial margin. This range accommodates both sustained high temperatures of fully-loaded servers and thermal shock of cold-start conditions. Our experience with thermal protection solutions across demanding operating environments informs material recommendations for reliability-critical applications.

The low outgassing characteristics — 0.18% TML and 0.03% CVCM per ASTM E595 — indicate material stability minimizing contamination risk in sealed enclosures. While these specifications derive from aerospace testing protocols, they provide useful benchmarks for data center applications where component cleanliness matters. Engineers working on applications requiring stringent outgassing performance can explore our advanced coatings and thermal management resources for additional material options.

Next Steps:

• DFM Best Practices for Thermal Management: Design guidelines for manufacturable thermal interface assemblies
• Precision Die Cut Thermal Interface Materials: When solid TIM formats provide the optimal solution
• Thermal Management: Prototype to Production: Scaling thermal solutions from development through high-volume manufacturing
• What to Expect from a Thermal Management Partner: Evaluating manufacturing partners for thermal interface applications

Alternative Thermal Interface Solutions Comparison

Engineers selecting thermal interface materials for data center applications typically evaluate several technology categories. Each approach offers distinct advantages depending on application requirements.

• Thermal gap pads: Pre-cut solid pads simplify assembly and accommodate larger gaps but may require higher compression force and offer limited conformability to surface irregularities. The THERM-A-GAP pad family includes options across multiple thermal conductivity levels — from THERM-A-GAP PAD 30 at 3.0 W/m-K for cost-sensitive applications to THERM-A-GAP PAD 60 delivering 6.0 W/m-K for higher-performance requirements.
• Thermal greases: Traditional pastes provide excellent initial contact but may suffer pump-out over time and complicate rework procedures.
• Phase change materials: These compounds soften at operating temperature to improve interface contact, offering thin bondline capability similar to greases with better stability.
• Dispensable gels: Materials like THERM-A-GAP GEL 40NS combine automation compatibility with long-term stability, making them attractive for high-volume manufacturing with demanding reliability requirements.

The optimal choice depends on specific application parameters including gap dimension, surface flatness, required thermal performance, production volume, and rework considerations. Applications requiring high electrical conductance alongside thermal management may benefit from specialized coating solutions complementing thermal interface materials.

Partner with Modus Advanced for Thermal Gel Applications

Modus Advanced works extensively with Parker Chomerics thermal interface materials, including the THERM-A-GAP gel product line. Our engineering team helps customers navigate material selection, design optimization, and production planning for thermal management applications.

Our thermal gel dispensing capabilities support projects from rapid prototypes through production volumes. The same engineering expertise guiding material selection extends into manufacturing execution — ensuring designs working in development translate successfully into production reality.

See It In Action:

• Thermal Management Applications: Explore thermal interface solutions across aerospace, defense, and commercial applications
• Medical Device Manufacturing Case Study: How thermal interface optimization enabled device assembly improvements
• Vertical Integration Benefits: Why single-source manufacturing accelerates thermal management projects
• Design for Manufacturability Services: Engineering support for thermal interface design optimization

Data center applications demand thermal performance directly impacting system reliability and operational efficiency. Partnering with a manufacturing team understanding both materials and application context accelerates the path from concept to qualified hardware.

Submit your design to our engineering team for a thermal management review. Because when your data center components need to perform reliably for years of continuous operation, getting the thermal interface right the first time matters.