Guide to Chomerics THERM-A-GAP Materials for Data Center Thermal Management

Data center thermal management has evolved from climate-controlled server rooms into sophisticated engineering challenges. The explosive growth of artificial intelligence workloads, cloud computing demands, and edge infrastructure has pushed processor power densities to levels that seemed impossible a decade ago. CPUs and GPUs now generate heat loads that demand precision thermal interface materials capable of efficiently transferring that energy to cooling systems.

The mathematics of data center thermal management are unforgiving. Every degree of temperature reduction at the component junction translates to improved reliability and extended operational life. Conversely, thermal interfaces that underperform create hot spots that trigger throttling, reduce efficiency, and accelerate component degradation. Modern data centers face thermal design power (TDP) requirements exceeding 1200W per processor in high-performance computing applications — a challenge that requires strategic material selection.

This guide examines specific products in the Parker Chomerics THERM-A-GAP material family, a comprehensive lineup of thermal interface materials engineered specifically for demanding data center applications. Engineers designing data center infrastructure will find detailed specifications, application guidance, and selection criteria to help match the right Chomerics thermal solution to each cooling challenge.

Essential 

• THERM-A-GAP PAD 60: High-Performance Thermal Interface Material
  A detailed look at PAD 60’s 6.0 W/m-K conductivity, compression characteristics, and ideal use cases in data center hardware—helping engineers understand when mid-range thermal pads deliver the best balance of performance and manufacturability.
• THERM-A-GAP PAD 80: Premium Cooling Performance for Critical Server Components
  Explains how PAD 80 provides 8.3 W/m-K thermal conductivity for high-power CPUs, GPUs, and AI accelerators, with guidance on when premium pads are required to meet aggressive thermal budgets.
• THERM-A-GAP GEL 30: Complete Guide to Dispensable Thermal Gels
  Covers GEL 30’s automation-ready workflow, thin bondline advantages, and best-fit applications in high-volume data center manufacturing, helping teams evaluate gel vs. pad strategies for modern server designs.

Thermal interface materials bridge the microscopic air gaps between heat-generating components and cooling systems in data center equipment. Air conducts heat poorly (approximately 0.026 W/m-K), so even small gaps create significant thermal resistance. Effective thermal interface materials fill these gaps with thermally conductive compounds that dramatically improve heat transfer efficiency in server environments.

The Chomerics THERM-A-GAP family divides into two primary categories: gap pads and thermal gels. Each category addresses different application requirements and manufacturing workflows in data center production. Understanding these distinctions helps engineers select the appropriate material format before diving into specific product comparisons for their thermal management needs.

Gap Pads: Solid Sheet Materials for Defined Interfaces

Gap pads arrive as solid sheet materials that are die-cut or converted into specific shapes matched to component footprints. These materials compress during assembly to conform to surface irregularities while spanning the gap between heat source and heat sink.

The pad format offers several advantages in data center applications. Die-cut pads provide consistent material placement during manual assembly operations. The solid form factor eliminates concerns about material migration or pump-out over the product lifecycle. Pads also accommodate larger gaps than thermal gels — spanning distances up to 5.0 mm (0.200") in some configurations.

Thermal Gels: Dispensable Precision for Automated Assembly

Thermal gels arrive as paste-like compounds that can be dispensed through automated equipment. These materials combine the conformability of a liquid with the stability of a cured compound, creating interfaces that maintain consistent thermal performance without the pump-out or dry-out issues that affect traditional thermal greases.

The dispensable format aligns well with high-volume data center manufacturing workflows. Automated dispensing systems place precise material volumes in programmed patterns, reducing labor costs and improving consistency across production runs. Gels also achieve thinner bondlines than pads (as thin as 0.10 mm or 0.004"), which minimizes thermal resistance in space-constrained designs common in modern server architectures.

The THERM-A-GAP pad family includes four materials that span the performance spectrum from cost-effective general-purpose options to premium high-conductivity solutions for demanding data center applications. Each material occupies a distinct position based on thermal conductivity, compression characteristics, and target applications.

PAD 30: Cost-Effective Performance for Secondary Heat Sources

THERM-A-GAP PAD 30 delivers 3.2 W/m-K thermal conductivity at a price point that makes sense for applications where premium materials would be overkill. The Shore 00 30 hardness creates a very soft, conformable material that deforms easily under minimal compression force.

This material excels in secondary thermal management applications. Memory modules, solid-state drives, voltage regulators, and network interface controllers all generate heat that requires management but rarely demands the absolute best thermal performance. PAD 30 provides adequate heat transfer at a sustainable cost when multiplied across hundreds or thousands of server installations.

The following specifications define PAD 30's performance envelope for data center applications:

PAD 30's deflection characteristics enable predictable thermal stack-up calculations. At 69 kPa (10 psi) compression, the material deflects approximately 26% from nominal thickness. This predictable behavior helps engineers design assemblies that achieve target compressed thicknesses without exceeding component stress limits.

PAD 60: High Performance for Demanding Data Center Applications

THERM-A-GAP PAD 60 steps up to 6.0 W/m-K thermal conductivity while maintaining low compression force characteristics for sensitive components. The Shore 00 40 hardness positions this material as slightly firmer than PAD 30 but still soft enough to protect sensitive semiconductor packages in server environments.

This material suits primary thermal interfaces where thermal budget constraints are tighter. Processor-to-heatsink interfaces in mid-range server configurations benefit from PAD 60's balance of performance and manufacturability. The material also serves well in applications where component height variations require a conformable interface that can adapt to surface irregularities.

PAD 60's outgassing characteristics deserve attention for enclosed server environments. With 0.05% total mass loss (TML) and 0.01% collected volatile condensable materials (CVCM) per ASTM E595, the material minimizes contamination risks in sealed enclosures where volatile compounds could affect nearby components.

PAD 80: Premium Thermal Conductivity for Critical Data Center Interfaces

THERM-A-GAP PAD 80 represents the high-performance end of the gap pad spectrum with 8.3 W/m-K thermal conductivity for the most demanding data center thermal management applications. This material targets the most thermally demanding applications where every fraction of a degree matters.

High-performance computing servers and GPU-accelerated AI infrastructure often require PAD 80's premium performance. These applications generate concentrated heat loads that stress cooling systems and demand the most efficient thermal pathways possible. The material's 0.97 °C-cm²/W thermal impedance at 1 mm thickness and 69 kPa (10 psi) compression enables engineers to meet aggressive thermal targets.

The Shore 00 35 hardness falls between PAD 30 and PAD 60, providing good conformability while maintaining structural integrity during handling and assembly. This balance proves valuable in production environments where material must be picked, placed, and compressed without tearing or excessive deformation.

PAD 80 is available in multiple carrier configurations to match different assembly requirements in data center manufacturing:

• PAD80 (unsupported): Maximum conformability and lowest thermal impedance when full compression is desired
• PAD80A (aluminum foil with PSA): Includes pressure-sensitive adhesive for permanent attachment to heatsinks
• PAD80G (woven glass carrier): Provides handling stability during die cutting and pick-and-place operations
• PAD80PN (PEN film carrier): Offers electrical isolation and dimensional stability

PAD 70TP: Thermal Putty for Permanent Installations

THERM-A-GAP PAD 70TP occupies a unique position within the pad family. The "TP" designation stands for "Thermal Putty," indicating behavior that differs fundamentally from conventional elastomeric pads. This material permanently conforms to mating surfaces during assembly and will not return to its original shape after compression.

The Shore 00 15 hardness makes PAD 70TP the softest material in the lineup. This extreme conformability enables the material to flow into surface irregularities, component warpage, and assembly tolerance variations more effectively than any other pad option. The 7.0 W/m-K thermal conductivity delivers premium performance to match this exceptional conformability.

Engineers should understand the one-time assembly implication before specifying PAD 70TP for data center applications. This material suits static installations where components will not be removed for service or replacement. Data center servers that operate continuously for years without component changes represent ideal applications. Designs requiring field serviceability or component replacement should consider conventional elastomeric pads instead.

The compression behavior of PAD 70TP differs dramatically from conventional pads. At just 69 kPa (10 psi), the material deflects 42% — nearly double the deflection of PAD 30 at the same pressure. This high deflection at low pressure means PAD 70TP achieves intimate surface contact without transmitting excessive mechanical stress to sensitive components.

Gap Pad Comparison Matrix

The following table enables direct comparison across the THERM-A-GAP pad lineup for data center thermal management:

The THERM-A-GAP gel family provides thermal interface solutions optimized for automated assembly and thin bondline applications in data center equipment production. All four materials arrive fully cured and ready to dispense — no mixing, no curing equipment, and no pot life concerns to manage during production.

GEL 30: Automation-Ready Standard Performance

THERM-A-GAP GEL 30 delivers 3.5 W/m-K thermal conductivity in a single-component dispensable format. The material achieves minimum bondlines of 0.10 mm (0.004") while maintaining the consistency required for automated dispensing operations.

This gel suits high-volume data center component manufacturing where thermal requirements are moderate but assembly efficiency is critical. Memory module cooling, SSD thermal management, and power supply applications all benefit from GEL 30's combination of adequate performance and automation compatibility.

The fully cured formulation eliminates pump-out concerns that affect liquid thermal compounds under thermal cycling. GEL 30 remains where dispensed, maintaining consistent thermal contact throughout the product lifecycle — a critical characteristic for data center equipment that operates continuously for years.

GEL 37: Visual Inspection Enabled

THERM-A-GAP GEL 37 provides 3.7 W/m-K thermal conductivity with one distinctive feature: a blue color that enables visual confirmation of material presence and coverage during quality inspection. This seemingly minor characteristic proves valuable in production environments where verifying thermal interface material application is part of the quality process.

The material's 30 g/min flow rate under standard test conditions indicates slightly better dispensability than GEL 30. This characteristic can translate to faster cycle times in automated dispensing applications where throughput affects overall production costs in data center manufacturing.

GEL 37 also supports rework scenarios without specialized solvents or abrasive removal processes. The material can be removed and reapplied during component replacement operations — a consideration for data center equipment where field service may be required.

GEL 40NS: Non-Silicone for Optical Applications

THERM-A-GAP GEL 40NS addresses a specific contamination concern that affects certain data center applications. The "NS" designation indicates a non-silicone formulation — this material uses a urethane-based binder system instead of the silicone chemistry found in other THERM-A-GAP products.

Silicone-based thermal materials release low molecular weight siloxanes that can contaminate sensitive optical and electrical surfaces. High-speed optical transceivers — increasingly common in data center switching infrastructure — use precision optical surfaces that silicone outgassing can degrade over time. GEL 40NS eliminates this compatibility concern while delivering 4.0 W/m-K thermal performance.

The operating temperature range differs from silicone-based alternatives. GEL 40NS performs reliably from -50°C to 125°C (-58°F to 257°F) — adequate for most data center applications but more constrained than the 200°C (392°F) upper limit of silicone formulations. Engineers should verify this range accommodates their specific thermal environment.

GEL 75: High-Performance Dispensable Solution for Data Centers

THERM-A-GAP GEL 75 brings 7.5 W/m-K thermal conductivity to the dispensable gel format. This material serves applications where both automated dispensing and premium thermal performance are required — a combination that proves valuable in high-performance computing server production.

The minimum bondline thickness of 0.20 mm (0.008") is thicker than the standard-performance gels. This characteristic reflects the higher filler loading required to achieve 7.5 W/m-K conductivity. Engineers should factor this bondline requirement into their thermal stack-up calculations.

GEL 75 excels in processor and GPU thermal interfaces where heat loads justify premium material costs. The material's low compression force characteristics protect sensitive BGA packages while the dispensable format supports high-volume production efficiency.

Thermal Gel Comparison Matrix

The following table enables direct comparison across the THERM-A-GAP gel lineup for data center applications:

Material selection for data center thermal management requires balancing multiple factors: thermal performance requirements, manufacturing constraints, component sensitivity, budget considerations, and long-term reliability expectations. The following framework helps engineers navigate these decisions systematically when choosing Chomerics thermal interface materials.

Selection by Component Type

Different data center components present distinct thermal interface challenges. The component type often provides strong guidance toward appropriate material categories.

• Processors and GPU accelerators: These high-power-density components justify premium thermal materials. PAD 80, PAD 70TP, or GEL 75 provide the thermal conductivity these applications demand. For automated assembly lines, GEL 75 offers dispensing compatibility with premium performance.
• Memory modules: DDR5 and high-bandwidth memory generate moderate heat loads across multiple packages at varying heights. PAD 30 or PAD 60 provide cost-effective thermal coupling at production volumes. GEL 30 or GEL 37 suit automated assembly workflows.
• Solid-state drives: Enterprise SSDs benefit from conformable materials that accommodate the varying component heights typical of drive designs. PAD 30 handles most SSD thermal requirements effectively. The thin bondline capability of GEL 30 or GEL 37 suits tight M.2 form factors.
• Optical transceivers: Applications near optical surfaces require GEL 40NS to eliminate silicone contamination risks. The material's 4.0 W/m-K conductivity handles typical transceiver thermal loads adequately.
• Voltage regulators and power electronics: These robust components tolerate higher compression forces and generate concentrated heat. PAD 60 or PAD 80 provide effective thermal pathways. The wide operating temperature ranges accommodate the elevated temperatures common in power conversion applications.

Selection by Manufacturing Requirements

Manufacturing workflow often constrains material format selection before thermal performance considerations come into play in data center production.

• Automated dispensing lines: Facilities with dispensing equipment should evaluate GEL materials first. The automation compatibility reduces labor costs and improves consistency at production volumes. GEL 30 and GEL 37 suit general applications while GEL 75 addresses high-performance requirements.
• Manual assembly operations: Die-cut pads simplify manual placement and provide visual confirmation of material presence. PAD 30, PAD 60, and PAD 80 serve manual assembly workflows effectively. The carrier options available for these materials improve handling during pick-and-place operations.
• High-mix, low-volume production: Prototype builds and specialty servers benefit from material formats that minimize setup and changeover time. Die-cut pads from sheet stock accommodate design variations without dispensing equipment reprogramming.
• Permanent installations: Equipment designed for continuous operation without field service suits PAD 70TP's permanent conformability characteristics. The thermal putty behavior provides exceptional surface contact in applications where component removal is not anticipated.

Material Selection Decision Matrix

The following matrix summarizes recommended Chomerics materials by primary application criteria for data center thermal management:

Successful thermal interface material implementation requires attention to several design and process parameters. Engineers should address these considerations during the design phase rather than discovering issues during prototype validation or production ramp.

Gap Analysis and Tolerance Stack-Up

The thermal interface gap (the distance between heat source and heat sink) determines both material selection and required thickness specification. Accurate gap analysis requires accounting for all tolerance contributions in the mechanical stack-up.

Key tolerance contributors in data center equipment include:

• Component height variation: Processor and memory package heights vary within manufacturing tolerances
• PCB thickness variation: Board thickness affects total stack-up height
• Heatsink flatness: Machined heatsink surfaces exhibit flatness tolerances
• Mounting hardware tolerances: Fastener and spring variations affect final compression
• Component warpage: BGA packages and heat spreaders may exhibit bow or twist

Engineers should calculate minimum and maximum gap dimensions across the full tolerance range. The selected pad thickness must span the maximum gap while achieving adequate compression at the minimum gap. Thermal gels offer more forgiveness for gap variation due to their ability to achieve thin bondlines when compressed.

Compression Force and Component Protection

Compression force directly impacts both thermal performance and component stress in data center applications. Higher compression improves surface contact and reduces thermal impedance, but excessive force damages sensitive components.

Modern BGA packages with thousands of solder joints are particularly vulnerable to compression-induced stress. The Shore 00 hardness ratings in the THERM-A-GAP lineup provide guidance for component compatibility:

• Shore 00 15 (PAD 70TP): Minimal compression force, suitable for the most stress-sensitive applications
• Shore 00 30 (PAD 30): Very low compression force, protects most BGA packages
• Shore 00 35 (PAD 80): Low compression force with good structural integrity
• Shore 00 40 (PAD 60): Moderate compression force, suitable for robust components

Engineers should verify that assembly compression forces remain within component stress limits throughout the expected compression range. Spring-loaded mounting systems help maintain consistent pressure across operating temperature variations in data center environments.

Carrier Selection for Manufacturing Efficiency

Pad materials are available in multiple carrier configurations that affect handling, assembly, and thermal performance. Carrier selection should align with production workflow requirements.

• Unsupported materials provide maximum conformability and the lowest thermal impedance. These configurations suit applications where mechanical capture maintains pad position and maximum thermal performance is required.
• Woven glass carriers improve tear resistance and handling stability during die cutting and pick-and-place operations. The carrier adds minimal thermal resistance while significantly improving manufacturing yield.
• Aluminum foil carriers with PSA enable pre-attachment to heatsinks or components before final assembly. This configuration simplifies assembly sequencing but adds material cost and slightly increases thermal resistance.
• PEN film carriers provide electrical isolation and dimensional stability. This option suits applications requiring additional dielectric protection beyond the base material's inherent isolation.

Thermal interface materials require precision converting to transform sheet stock into custom parts matched to specific component footprints and heatsink interfaces in data center equipment. The converting method selection depends on part geometry, production volume, and material characteristics.

Converting Method Options

Each converting approach offers distinct advantages for different data center production scenarios:

• Die cutting: Provides cost-effective production at volume once tooling investment is justified; delivers excellent consistency for simple to moderate geometries
• CNC cutting: Eliminates tooling lead time and cost for prototypes and lower volumes; accommodates rapid design iteration during development
• Waterjet cutting: Handles thicker materials and complex geometries; produces precise cuts without heat-affected zones that could alter material properties

Material properties influence converting method selection. Softer materials like PAD 70TP require careful handling during converting to prevent deformation. Carrier-backed materials generally convert more reliably than unsupported configurations.

Tolerance Expectations

Standard converting tolerances for thermal interface materials follow elastomeric converting practices. Dense pad materials typically achieve ±0.38 mm (±0.015") for dimensions under 25.4 mm (1.0"). Larger features and thicker materials require appropriately wider tolerances.

Tighter tolerances remain achievable through specialized fixturing and process optimization. Engineers requiring tighter specifications should engage early with their manufacturing partner to evaluate feasibility, lead time implications, and cost impact. Design engineers should specify tolerances that reflect actual functional requirements — unnecessarily tight tolerances increase cost and lead time without improving thermal performance.

Thermal Gel Dispensing Considerations

Gel materials require dispensing equipment and process development to achieve consistent application in data center manufacturing. Key dispensing parameters include:

• Dispense pattern: Dot, serpentine, spiral, or custom patterns optimize coverage based on component geometry
• Material volume: Controlled deposit volumes ensure complete coverage without excessive squeeze-out
• Process temperature: Consistent material temperature promotes repeatable flow characteristics
• Equipment maintenance: Regular tip replacement and system cleaning maintain dispensing consistency

Production dispensing parameters will vary based on specific equipment configurations, tip geometries, and environmental conditions. Process development should establish parameters that deliver consistent material volume and pattern geometry before production release. Working with a partner that has experience dispensing thermal gels can accelerate production.

Data center equipment manufacturers maintain rigorous quality management systems. Thermal interface material suppliers and converters must demonstrate the certifications and processes necessary to support these requirements.

All THERM-A-GAP materials carry UL 94 V-0 flammability ratings and RoHS compliance — baseline requirements for data center equipment. The low outgassing characteristics across the product family minimize contamination risks in enclosed server environments.

Manufacturing partners should maintain:

• ISO 9001 certification: Foundational quality management framework
• Material traceability: Lot tracking and documentation supporting warranty and failure analysis
• Dimensional inspection capability: Verification that converted parts meet specifications

Modus Advanced works extensively with Parker Chomerics thermal interface materials, including the complete THERM-A-GAP product family. Our engineering team helps data center equipment manufacturers navigate material selection, design optimization, and production planning for thermal management applications.

Engineers make up more than 10% of our staff — a deliberate investment that enables meaningful design feedback rather than simple order processing. Our team understands both the thermal requirements driving material selection and the manufacturing considerations that affect cost, quality, and lead time in data center production.

Our capabilities for Chomerics THERM-A-GAP materials include:

• Die cutting, CNC cutting, and waterjet cutting for converting pad materials to custom geometries
• Thermal gel dispensing for automated application of GEL materials
• Design for manufacturability review to optimize thermal interface designs before production
• Rapid prototyping for design validation and qualification testing

Our vertically integrated operations enable us to combine thermal interface material converting with complementary manufacturing processes including CNC machining, assembly, and inspection services. This integration reduces lead times and simplifies supply chain management for complex data center components.

Quality systems certified to ISO 9001 standards ensure consistent manufacturing outcomes. Whether you're prototyping a new server design or scaling to production volumes, we can support your program from design through ongoing procurement.

Submit your design to our engineering team for material selection guidance and a detailed manufacturability review. We strive to turn quotes around within 48 hours — because when your data center infrastructure needs to reach deployment sooner, one day matters.