Thermal Impedance & TIM Testing Services (ASTM D5470)
Thermal characterizations according to ASTM D5470
Why Do We Need to Measure the Thermal Conductivity of TIMs?
As electronic devices continue to shrink in size while increasing in power density, the role of Thermal Interface Materials (TIMs) in managing heat becomes critical. Accurately characterizing the thermal conductivity of TIMs is essential for optimizing thermal management in high-performance applications such as electric vehicle components, aerospace, and electronics.
Accurate Thermal Characterization for High-Performance Applications
TIMs are essential for the reliability, efficiency, and longevity of modern electronic systems. At Thermal Analysis Labs (TAL), we provide precise, application-relevant characterization of TIMs, delivering the data scientists and engineers need to optimize thermal designs, validate materials, and ensure long-term performance.
TIM applied to an IC for optimized thermal conduction
Using industry-recognized methodologies and advanced laboratory instrumentation, including the ZFW TIM Tester platform, we deliver precise measurements of heat transfer performance, interface resistance, and long-term reliability. Built on a strong research foundation, our testing capabilities support both industrial material qualification and advanced R&D programs with dependable, application-relevant data.
For more information on measuring thermal conductivity of TIMs with modified transient plane source method, click here.
What We Measure
Our TIM testing services provide detailed characterization of the thermal and mechanical performance of materials used for heat management in high-power electronics, power modules, semiconductor devices, and advanced packaging assemblies. Key properties evaluated include:
- Thermal Resistance – Quantifies resistance to heat flow through the material under controlled pressure and thickness conditions.
- Effective Thermal Conductivity – Calculated from precise bond-line thickness and thermal resistance measurements to assess real-world heat transfer capability.
- Bond-Line Thickness – High-accuracy measurement of compressed sample thickness under applied load.
- Interfacial (Contact) Thermal Resistance – Resistance to heat flow at the interfaces between the TIM and adjoining surfaces.
- Pressure- and Gap-Dependent Performance – Characterization of thermal behavior across a range of applied pressures and mechanical gaps.
TIM Tester
The TIM Tester positions a material sample between two precisely controlled meter bars, one heated and one cooled, to establish a stable heat flow. Embedded high-resolution sensors monitor temperatures and heat flux, allowing accurate computation of thermal properties as a function of thickness and applied pressure. Multiple measurement modes enable testing of low-viscosity pastes, soft pads, adhesives, and solid materials across relevant operating conditions.
Technical Data – TIM Tester
| Property | Value |
|---|---|
| Resolution & reproducibility | < 1 mm²·K/W |
| Measuring range: Surface pressure | 0.05–2 N/mm² (7.25–290 PSI) |
| Measuring range: Gap | 0–10 mm |
| Measuring range: Sample medium temperature | 10–150 °C (50–302 °F) & 175 °C (347 °F)* |
*Maximum hot side temperature
Typical Applications
Our TIM testing services support engineers and manufacturers working in:
- Power electronics cooling
- Battery pack thermal safety validation
- Semiconductor packaging
- Heat spreader design
- Automotive and aerospace electronics
- Material R&D and quality control
- Reliability and life-cycle evaluation
The TAL Advantage
When you partner with Thermal Analysis Labs, you receive more than test data:
- Expert Consultation – Dedicated technical support from inquiry to final report
- Fast Turnaround – Efficient scheduling to meet development timelines
- Expedited Testing – Available for time-sensitive development programs
- Application Insight – One-on-one review of results
- Proven Reliability – Trusted by engineers and research teams worldwide for accurate, repeatable, and application-relevant data.
Ready to Start Your Project?
Contact Thermal Analysis Labs (TAL) to discuss your TIM testing requirements, request a quote, or schedule a material evaluation.
Our team will work with you to develop a customized test plan tailored to your materials, industry standards, and performance objectives.
Materials we test
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Thermal Interface Materials (TIMs)
Polymers & Composites
Phase Change Materials
Metals & Alloys
Aerogels
Thin Films
Heat Transfer Fluids
Batteries & Battery Packs -
Glass & Ceramics
What Our Customers Say…
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Thermal Analysis Lab was great to work with—flexible, responsive, and reliable. We highly recommend their testing services.
Narsimhan RaghunathanPresident -
TAL offers professional services ranging from analytical testing to customer support. The turnaround time for testing is relatively fast, and the data provided is reliable. They are available to answer any questions we may have.
Yukihiro HaraR&D Manager – Moses Lake Industries -
All data and reports were very helpful and we appreciate your support; you did an amazing job to conduct the tests and confirm the reports within such a short time frame. This really helped us get out of jam and your support meant a lot to our efforts with our customer. We will certainly contact you again on these matters.
Chris EbelingMichael Smith, Managing Director, MAE Trading International Inc -
I just want to thank you for your support to have my sample thermal conductivity analysis swiftly carried out. The paper has been accepted in the journal of materials science: materials in electronics. [comment on Transient Plane Source (TPS) method]
Ekene OkaforResearch Scholar, University of Arkansas
Frequently Asked Questions
There are several established methods for testing TIMs, and the best choice depends on your specific requirements.
MTPS (Modified Transient Plane Source) is the simplest, fastest, and most automated method available for TIM characterization. C-Therm’s patented MTPS technology is exclusive to the Trident Thermal Conductivity Platform and is widely used for rapid screening and formulation development. The method is uniquely effective at detecting filler sedimentation and agglomeration, major factors that degrade TIM thermal performance. MTPS is also valuable for material selection and at-line or in-line quality control, where consistency in TIM application is critical. Its high level of automation contributes to industry-leading precision (<1%). MTPS is compliant with ASTM D7984 and suitable for testing TIMs in many formats, including pads, tapes, pastes, adhesives, and phase-change materials.
Important note: C-Therm is the only supplier of true MTPS. Other vendors referencing “MTPS” are typically referring to a single-sided TPS adaptation, which lacks the patented guard-ring design, automation, accuracy, and precision of MTPS. ISO 22007-2 explicitly cautions against using single-sided TPS configurations where a traditional double-sided TPS setup is possible, as single-sided arrangements are known to introduce significantly higher measurement error.
TPS (Transient Plane Source), the double-sided hot disc method, is compliant with ISO 22007-2 and GB/T 32064 and is one of the two most frequently cited methods on TIM technical datasheets. It is better suited to advanced users because it allows detailed control over parameters such as test time and power. TPS can also characterize anisotropic thermal conductivity when density and heat capacity are known. It complements MTPS extremely well, and both methods are available on the C-Therm Trident platform, which is widely regarded as the leading solution for TIM thermal conductivity testing.
ASTM D5470 (TIM Tester) is the primary steady-state method used to measure thermal impedance. C-Therm supplies the world-leading TIM Tester from ZFW and also provides ASTM D5470 testing services through Thermal Analysis Labs. Unlike thermal conductivity—which is intrinsic—thermal impedance incorporates thickness, surface roughness, and contact quality, all of which significantly influence heat transfer in electronics. Even a material with high thermal conductivity may perform poorly if its impedance is high. While highly relevant for real-world interface performance, D5470 does not provide anisotropy information, cannot easily detect issues such as filler dispersion or agglomeration, and generally requires much longer test times (hours versus minutes).
Each of these methods offers distinct advantages, and together they provide a comprehensive toolkit for accurately evaluating the thermal performance of TIMs.
TIM testing confirms a material’s thermal conductivity, thermal resistance or impedance, heat-spreading capability, and interface quality. These measurements are essential for predicting real-world performance, preventing overheating, and ensuring reliability under operating temperatures and pressures. Accurate characterization helps improve device efficiency and long-term stability in electronics, EV batteries, telecommunications equipment, and other high-power systems.
Yes. Anisotropy (in-plane vs. through-plane conductivity) can be measured using TPS (ISO 22007-2) when density and heat capacity are known.
We typically require small, flat samples, about 30 mm max square or a few centimeters in diameter, with thicknesses of a few millimeters, depending on the method. Exact sample requirements vary by technique (TIM Tester, MTPS, TPS, or LFA), so please contact us for guidance based on your specific TIM.
Yes. TIM Tester, MTPS and TPS can test PCMs, greases, gels, and adhesives. Additional sample containment may be recommended depending on viscosity.
TIM performance is influenced by:
- Compression state / applied pressure
- Temperature
- Quality of interface contact
- Filler type, size, and loading
- Dispersion quality (agglomeration/sedimentation)
- Polymer matrix composition
- Cure state (for adhesives)
- Thickness and mechanical properties
Typical turnaround time is 2 to 3 business weeks, depending on the sample type, testing method, and current workload. Expedited testing is available for an additional surcharge and can reduce the turnaround time to as little as a few days
You may submit a single sample or multiple samples, or request a quote, by contacting us through our online form, email, or call us at +1-877-827-7623 (toll-Free) or +1 (506) 457-1515 (international). Please provide details about your material, sample count, sample sizes, and desired testing parameters to ensure an accurate quote.