Chomerics THERM-A-GAP PAD 80: High-Performance Thermal Interface Material for Data Center Applications

Understanding PAD 80 Thermal Interface Materials

PAD 80 thermal interface material addresses a fundamental challenge in server thermal design — transferring heat efficiently from components to heat sinks across variable gap distances. Data center thermal loads continue climbing as processing densities increase, with modern GPUs reaching thermal design power levels exceeding 1200 watts. Understanding the keys to thermal dissipation using thermal interface materials determines whether these high-performance systems operate reliably or fail under load.

Parker Chomerics THERM-A-GAP PAD 80 is a thermally conductive gap filler pad engineered specifically for applications where superior heat transfer must be maintained across gaps ranging from 0.51 mm to 5.10 mm (0.020" to 0.200").

The material's 8.3 W/m-K thermal conductivity positions it as a high-performance solution for data center applications where thermal resistance directly impacts component reliability and system uptime. For applications requiring lower thermal conductivity with reduced cost, engineers may also consider THERM-A-GAP PAD 60 thermal interface material for data center applications.

Essential Background Reading:

• 5 Keys to Thermal Dissipation: Foundational concepts for understanding heat transfer in electronic assemblies
• Complete Engineer's Guide to Thermal Management: Comprehensive overview of thermal interface material selection and application
• Thermal Interface Materials – Making the Right Choice: Decision framework for selecting between gap pads, gels, and other TIM formats
• Understanding Thermal Contact Resistance: Technical deep-dive into interface resistance and heat transfer optimization

Data Center Thermal Management Challenges

Servers function as purpose-built computers designed to store and manage large data volumes while delivering computing power to networked clients. Each server contains multiple heat-generating components — processors, memory modules, power supplies, and storage devices — that must operate within strict temperature envelopes to maintain reliability.

Air gaps and surface irregularities between mating surfaces create thermal resistance that impedes heat flow. Thermal interface materials bridge these gaps, but selecting the right material requires balancing thermal performance against mechanical constraints, assembly requirements, and cost.

High-performance computing and AI workloads generate substantially more heat per unit volume than traditional enterprise applications. This increased thermal burden places greater emphasis on thermal interface material selection during the design phase, making materials like PAD 80 critical for maintaining system reliability. Engineers working on high-temperature applications requiring enhanced durability face similar thermal management challenges across aerospace and defense environments.

PAD 80 Thermal Performance Specifications

The material's thermal properties determine its effectiveness in server applications. Understanding these specifications enables engineers to calculate expected thermal performance in their specific designs.

Thermal impedance represents the total resistance to heat flow through the interface, including both bulk material resistance and contact resistances at mating surfaces. The 0.97 °C-cm²/W value at 69 kPa (10 psi) and 1 mm thickness provides a baseline for thermal calculations, though actual performance varies with applied pressure and gap thickness in specific applications. For designs where lower thermal conductivity meets requirements at reduced cost, THERM-A-GAP PAD 30 offers a practical alternative for data center thermal management.

Related Content:

• THERM-A-GAP PAD 60 Material Guide: Lower thermal conductivity alternative for cost-sensitive data center applications
• THERM-A-GAP PAD 30 Material Guide: Entry-level gap filler option for standard thermal management requirements
• THERM-A-GAP GEL 75 for Data Centers: Dispensable thermal gel alternative for complex geometries
• THERM-A-GAP GEL 40NS Non-Silicone: Silicone-free thermal gel for sensitive optical or electrical environments
• Parker Chomerics Thermal Material Guide: Complete overview of the Chomerics thermal interface material portfolio

Compression and Deflection Characteristics

PAD 80's deflection behavior determines both final bond line thickness and thermal impedance achieved in the assembled state. Understanding compression response is essential for proper thermal design.

The following deflection data was measured on 3.05 mm (0.120") thick unsupported samples:

At typical server assembly pressures of 69 kPa (10 psi), engineers can expect approximately 25% deflection from nominal pad thickness. This predictable behavior supports accurate stack-up calculations during mechanical design phases. For applications where dispensable materials better suit the geometry, THERM-A-GAP GEL 75 provides an alternative approach for data center thermal management.

PAD 80 Carrier Configurations

PAD 80 is available in four configurations addressing different assembly and performance requirements:

• PAD80A (Aluminum foil with PSA): The aluminum foil carrier provides structural support and heat spreading capability, while the pressure-sensitive adhesive enables permanent attachment to heat sinks or enclosures during assembly.
• PAD80G (Woven glass carrier): The glass carrier is offset to one side and provides reinforcement without adhesive, working well when mechanical clamping maintains contact pressure throughout the product's service life.
• PAD80PN (PEN film carrier): The polyethylene naphthalate film offers alternative reinforcement without adhesive, suitable for applications requiring electrical isolation and dimensional stability.
• PAD80 (Unsupported): The unreinforced material offers maximum conformability and the lowest thermal impedance, appropriate when full material compression is desired and handling during assembly permits.

Minimum thicknesses vary by carrier type. PAD80G requires a minimum thickness of 0.51 mm (0.020"), while PAD80A and PAD80PN start at 0.76 mm (0.030"). Unsupported PAD80 is available down to 1.02 mm (0.040").

Electrical Isolation Properties

Many server thermal management applications require electrical isolation between components and heat sinks or chassis surfaces. PAD 80's volume resistivity of 10¹⁴ ohm-cm ensures negligible current leakage even at elevated operating temperatures. Engineers designing systems that require high electrical conductance thermal control coatings for satellite and aerospace applications face different requirements where conductivity rather than isolation is the priority.

Combined with a dielectric strength of 5.0 kVAC/mm (125 VAC/mil), PAD 80 provides reliable electrical isolation in applications where heat-generating components must be thermally connected but electrically separated from grounded surfaces. The dielectric constant of 6.0 at 1,000 kHz and dissipation factor of 0.002 indicate low electrical losses. For applications requiring silicone-free materials, THERM-A-GAP GEL 40NS non-silicone thermal gel offers an alternative formulation.

Regulatory Compliance for Data Center Equipment

Data center equipment must meet various regulatory standards. PAD 80 addresses several key requirements relevant to server applications.

The UL 94 V-0 flammability rating confirms self-extinguishing behavior, a baseline requirement for materials used in enclosed electronic equipment. Full details are available in UL File E482354. RoHS compliance simplifies procurement and qualification for equipment destined for global markets.

Design Guidelines for Server Applications

Selecting appropriate PAD 80 thickness requires careful consideration of thermal stack-up tolerances. Engineers should calculate minimum and maximum gap distances between heat-generating components and heat sinks across the full range of manufacturing tolerances.

Key design considerations include:

• Gap tolerance analysis: Add worst-case tolerances for component height, PCB thickness, heat sink flatness, and mounting hardware. Pad thickness should exceed the maximum gap while providing adequate compression at the minimum gap.
• Compression target: Aim for 20-40% compression in the assembled state to achieve optimal thermal performance without excessive mechanical stress. This corresponds to pressures between approximately 69 kPa and 172 kPa (10-25 psi) based on deflection data.
• Carrier selection: Choose the aluminum foil carrier with PSA when permanent attachment simplifies assembly or when the foil's lateral heat spreading contributes to system thermal performance. Select unsupported material when maximum compression and minimum thermal impedance are priorities.
• Thickness tolerance: Sheet thickness tolerance is ±10% of nominal thickness or ±0.25 mm (±0.010"), whichever is smaller. Factor this tolerance into gap calculations.

Converting PAD 80 for Custom Applications

Modus Advanced provides die cutting, CNC cutting, and waterjet cutting capabilities to transform PAD 80 sheet stock into custom parts matched to thermal interface requirements. Our converting expertise allows us to produce parts from prototype quantities through production volumes while maintaining dimensional consistency.

For complex server assemblies with multiple thermal interfaces, our engineering team can review designs and provide feedback on part geometry, tolerance feasibility, and material utilization. More than 10% of our staff are engineers who understand both the thermal requirements driving material selection and the manufacturing considerations that affect cost and lead time.

Our AS9100 and ISO 9001 certifications reflect quality systems built for aerospace and defense applications — systems that translate directly to the precision requirements of data center thermal management components. Whether prototyping a new server design or scaling to production volumes, we can support programs from design through ongoing procurement.

Next Steps:

• Thermal Gap Pad Compression Guide: Detailed guidance on optimizing compression for maximum thermal performance
• Understanding Thermal Impedance: Critical design parameters for calculating heat transfer in your assembly
• Precision Die-Cut Thermal Interface Materials: Custom converting options when standard shapes don't meet your requirements
• DFM Best Practices for Thermal Management: Design for manufacturability guidance specific to thermal interface applications
• Advanced Thermal Gel Dispensing: Alternative dispensing approach for high-volume or complex thermal applications

Frequently Asked Questions About PAD 80

What thermal conductivity does PAD 80 provide?

PAD 80 delivers 8.3 W/m-K thermal conductivity, measured according to ASTM D5470. This thermal conductivity level suits high-density server environments where effective heat dissipation is critical for system reliability and prevents thermal throttling of processors and memory.

Which carrier configuration should I specify for my application?

Carrier selection depends on your assembly requirements and thermal performance priorities. PAD80A with aluminum foil and pressure-sensitive adhesive simplifies automated assembly and provides additional heat spreading. PAD80G with woven glass suits applications requiring mechanical clamping. Unsupported PAD80 offers maximum compression and lowest thermal impedance when handling during assembly permits.

What compression force does PAD 80 require?

PAD 80's Shore 00 hardness of 35 enables effective thermal contact at relatively low compression forces. At 69 kPa (10 psi), the material achieves approximately 25% deflection. Target 20-40% compression in your assembled state to balance thermal performance with mechanical stress on sensitive components.

What temperature range can PAD 80 withstand?

PAD 80 operates reliably from -55°C to 200°C (-67°F to 392°F). This broad operating temperature accommodates both standard data center environments and high-ambient conditions where air conditioning capacity may be limited or where equipment operates in partially outdoor installations.

Does PAD 80 provide electrical isolation?

Yes. PAD 80's volume resistivity of 10¹⁴ ohm-cm and dielectric strength of 5.0 kVAC/mm provide reliable electrical isolation between thermally connected but electrically separated surfaces. This property is essential when components must transfer heat to grounded chassis or heat sink surfaces.

What flammability rating does PAD 80 meet?

PAD 80 achieves UL 94 V-0 flammability rating, confirming self-extinguishing behavior required for materials used in enclosed electronic equipment. This certification simplifies qualification for enterprise-grade server applications and meets baseline safety requirements for data center equipment.

See It In Action:

• Thermal Management Applications: Explore how Modus supports thermal interface material converting across industries
• Medical Device Manufacturing Case Study: How precision converting solved assembly challenges for a medical device partner
• Thermal Products: Prototype to Production: Understanding the manufacturing journey for thermal interface components
• Custom Gasket Manufacturing Capabilities: Die cutting, waterjet, and CNC cutting for precision thermal interface parts

Working with Modus Advanced

Thermal interface material selection represents just one element of successful server thermal design. The right material must also be converted accurately and delivered reliably to support production schedules.

Our vertically integrated capabilities allow us to source PAD 80 material, convert it to specifications, and deliver finished parts with shorter lead times than multi-vendor approaches typically require. This integration simplifies supply chains and reduces coordination overhead that comes with managing separate material and converting suppliers.

Submit designs to our engineering team for a design for manufacturability review and quotation. We strive to return quotes within 48 hours so development programs can keep moving forward. Because when data center customers are counting on reliable thermal performance, the precision of every component matters.