PTM 7950 | Phase Change Pad
- 0.04 Thermal Impedance
- 8.5 Thermal Conductivity
- Pad Form
PTM7950 is a super highly thermally conductive Phase Change Material (PCM). It is designed to minimize thermal resistance at interfaces, maintain excellent performance through reliability testing, and provide scalable application at a competitive cost. Based on a novel polymer PCM system, PTM7950 exhibits excellent interface wettability during typical operating temperature ranges, resulting in extremely low surface contact resistance. Since PTM7950 comes only in 0.25mm and 0.2mm (thicker versions are under development) you need to be sure that this thickness is compatible and suitable for the flatness of your package.
Available Versions: (Check the difference between pad and paste version)
- PTM7950 Pad, easy apply and no drying steps
- PTM7950-SP, paste version for automatic stencil printing
- PTM7950-SPS, paste version with slow drying solvent
PTM 7950 cannot come in pad form on a reel. This is because the material is too soft and tends to wrinkle when rolled, especially when the size gets larger.
- Super low thermal impedance (TI vs Pressure Curve PTM7950)
- Silicone-free, no pump out, bleed out, dry out issue
- Industry proven superior long-term reliability (Reliability Report PTM7950)
- Min BLT~20um, typical BLT is below 50um (BLT vs Pressure Curve PTM7950)
- 30~40 psi pressure is needed for usage (PCM Application Note)
Highly Recommend For:
- Power modules/inverters in automotive and power applications
- High performance IT/enterprise computing devices
- Consumer electronics, high performance IC
- High power LED
Know More about PTM7950's superior thermal performance and long-term reliability.
| Specific Gravity |
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume.
For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
|Thickness range||0.25 mm|
| Volume Resistivity |
Volume resistivity, also called volume resistance, bulk resistance or bulk resistivity is a thickness dependent measurement of the resistivity of a material perpendicular to the plane of the surface.
| Thermal Conductivity |
Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance.
Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system.
|Thermal Impedance||0.04 °C·cm²/W|
Honeywell PTM7950 is one of the most successful TIM products used in high power inverters and high performance computing devices. Ultra-low thermal impedance with minimum achievable BLT and superior long-term reliability make PTM7950 stand out from the competitors. PTM7XXX series also presents stability among vertical applications and pass automotive standard vibration test (Check the Vibration & Shock Test Report), thus PTM7XXX is currently widely used in automotive applications such as power inverters.
What are the reliability expectations of the PTM7950?
All the 7XXXseries (PTM7000, PTM7900 & PTM7950) pass the three major reliability tests with flying colours. Honeywell does not test beyond 1000 cycles, 92 hrs HAST and 1000 hrs HTS. However, anecdotally, some automotive customers have taken 7900 to beyond Honeywell’s limits and have found it to pass shock and vibration, longer temperature cycling and longer temperature and humidity soak. (Check Reliability Report PTM7950)
If your lifetime performance is defined mainly by power cycling, then you also check the PTM6000 series which will have the longest life. The main difference between the 7XXX products is the filler content which makes PTM7950 the most conductive.
How to achieve the minimum thermal resistance of PTM7950?
To achieve as low thermal resistance as possible for your device, you choose the material with high thermal conductivity, minimize the bondline thickness, and also improve the surface wettability. PTM7950 excels at the thermal performance since it could achieve minimum bondline as 17um and high TC as 8.5 W/m.K. Clamping pressure (30~40 psi) and temperature (at least 30mins@60°C) are suggested to achieve a minimum bond line thickness of the phase change material, typically less than 1.5 mil (0.038mm) for best performance. The material must go through the phase change temperature to exhibit entitlement performance. (Check PCM Application Note) .
The figures below shows the TI achieved using PTM7950.