There is a growing demand across industries for higher computational capacity, faster data processing, and improved electronic reliability. From AI servers and supercomputers to automotive electronics and advanced telecom infrastructure, one common critical factor directly impacts performance and long-term stability: effective thermal management.
To address this challenge, Honeywell introduces PTM6880, a next-generation phase change material (PCM) engineered for superior heat dissipation and long-term reliability. PTM6880 overcomes the common “pump-out” failure seen in traditional thermal interface materials, delivering stable and reliable thermal performance even under extreme operating conditions.
The Pump-Out Problem in Thermal Interface Materials
Pump-out occurs when a thermal interface material (TIM) is forced out of the gap between a processor or chip and its heatsink. As the TIM migrates, it leaves behind air gaps that disrupt efficient heat transfer, leading to higher operating temperatures, reduced reliability, and potential device failure.
This issue is often triggered by thermal expansion and contraction of the interface surfaces during rapid temperature cycles. The repeated stress causes “warpage,” or the bending of once-flat surfaces. As warpage progresses, the TIM is gradually pushed out of the interface, leaving insufficient material to fill the gaps, ultimately resulting in poor thermal conductivity and overheating risks.
How Honeywell PTM6880 Solves Pump-Out with Stable Thermal Impedance
Honeywell’s PTM6880 is a phase change thermal interface material (PCM) engineered to prevent pump-out. Unlike conventional PCMs, it uses a new polymer resin system that withstands warpage up to 120 μm, with ongoing R&D efforts to extend the limit to 300 μm.
| Property | Value | Advantage |
|---|---|---|
| Thermal impedance (no shim) | 0.056 °C∙cm²/W | Ensures minimal resistance to heat flow |
| Thermal conductivity | 6 W/m∙K | Efficient heat flow |
| Bond line thickness (60°C, 20 psi) | 20 μm | Supports ultra-thin gap tolerances |
| Density | 2.7 g/cm³ | Consistent and reliable film uniformity |
To evaluate the pump-out resistance of PTM6880, a thickness cycling test was conducted to simulate the mechanical stresses and warpage that occur in real electronic assemblies during power cycling. In this test, the sample was repeatedly compressed and released between two test heads to simulate the expansion and contraction of components under changing temperature. The gap between the test heads alternated from 120 µm (expanded) to 70 µm (compressed) in one complete cycle, and this process was repeated up to 750 cycles. The test was conducted using Thermal Interface Material Analyzer (TIMA) 5 which enables in-situ thermal resistance measurements during thickness cycling. TIMA 5 measurements were all carried out automatically and based on ASTM D 5470: Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulation Materials.
During the test, the thermal resistance (K/W) of the material was monitored. Increasing trend in thermal resistance over repeated cycles indicates that the material is losing interfacial contact, which can be attributed to pumping-out. In contrast, consistent thermal resistance values reflect good material adhesion and mechanical stability under cyclic stress.
The results show that PTM6880 maintained a consistent thermal resistance throughout the cycling test, while the commercially available PTM7950 exhibited a steady increase in thermal resistance as cycling progressed. Specifically, after 750 cycles, PTM6880 showed only a 30–42% increase, compared to 85–119% for PTM7950, depending on the test gap. This is a clear indication that PTM6880 has better pump-out resistance and maintains good interfacial contact during pump-out cycling.
In order to further support this finding, PTM6880 is subjected to reliability tests, such as thermal aging at 150 °C and a thermal shock test ranging from –40 °C to 125 °C as shown in the test graph. Consistent thermal resistance results was observed over a duration of 1000 hours, indicating no degradation or pumping out took place during the span of both tests.
The pumping out evaluation done on PTM6880 supported by thermal aging and shock tests had delivered positive results, which ensured consistent thermal performance and improved long-term reliability of electronic devices.
Why Minimizing Pump-Out Matters
Pump-out is a critical challenge in thermal management, especially in applications where performance and reliability cannot be compromised. In data centers, processors and accelerators demand continuous uptime and consistent thermal performance. Any material that loses contact due to pump-out can overheat and have reduced efficiency. The same issue appears in automotive power electronics, particularly in SiC and GaN inverters, which face harsh operating environments and constant temperature fluctuations. Likewise, 5G and telecom devices, with their dense board layouts, have little tolerance for thermal failures and require PCMs that remain stable under stress.
Another benefit of minimizing pump-out is less down-time and less cost of rework throughout the operating life of the device. When a TIM maintains consistent contact and thermal performance, systems remain in operation for longer periods without requiring intervention. In contrast, materials that suffer from pump-out can lead to performance drift, which often necessitates costly disassembly and reapplication. By preventing these issues, low pump-out materials such as PTM6880 not only improve thermal reliability but also contribute to longer service life and lower total cost of ownership.
This is where Honeywell PTM6880 makes a difference. Unlike conventional PCMs, it combines high thermal conductivity, excellent phase change stability, and strong resistance to pump-out. For engineers, this means dependable long-term performance even as devices continue to scale in power density. PTM6880 helps processors, inverters, and communication systems stay cool, consistent, and reliable.
High Powered Applications for PTM6880
The PTM6880 is ideal for industries pushing the limits of performance and reliability.
- AI Servers & Supercomputing
- Data Centers (see: How can Thermal Interface Materials enhance the efficiency and reliability of HPC & Data Center) & Networking Equipment
- Automotive Electronics (EV inverters, OBC, DC/DC converters, IGBT modules)
- Telecommunications Infrastructure
Major GPU makers and leading data center companies have already tested and validated PTM6880, confirming its superior thermal resistance, better hotspot management, and more consistent temperature distribution compared to the next best PCM alternative.
Ready to see the difference for yourself? Get in touch with us today to learn how PTM6880 can upgrade your thermal management strategy.
