RT/duroid 6035HTC is a ceramic-filled PTFE laminate that combines microwave dielectric performance with improved thermal conduction relative to many conventional RF laminates. It is relevant to circuits where power dissipation and transmission loss interact. The thermal-conductivity test method must remain attached to the quoted value when comparing it with TC materials.
Material system
Ceramic-filled PTFE
Technical properties
| Property | Reported value | Conditions / source |
|---|---|---|
| Process dielectric constant | 3.50 ± 0.05 | Typical, 10 GHz, 23°C; IPC-TM-650 2.5.5.5 clamped stripline; direction is not separately recorded here. Source |
| Design dielectric constant | 3.6 | Typical, 8–40 GHz; differential phase length method. Average across the common constructions in the cited datasheet. Source |
| Dissipation factor | 0.0013 | Typical, 10 GHz, 23°C; IPC-TM-650 2.5.5.5; direction is not separately recorded here. Source |
| Thermal conductivity | 1.44 W/(m·K) | Typical; ASTM C518, 80°C; through-thickness thermal conduction. Source |
| Thermal coefficient of dielectric constant | -66 ppm/°C | Typical; -50°C to 150°C, IPC-TM-650 2.5.5.5 (modified temperature measurement); 10 GHz. Source |
| Water absorption | 0.06 % | Typical; D24/23, IPC-TM-650 2.6.2.1 / ASTM D570. Source |
| Density | 2.2 g/cm³ | Typical; 23°C, ASTM D792. Source |
Typical reported values are not a purchase specification. Process Dk, design Dk and values measured at different frequencies are not interchangeable.
Selection and design notes
- Consider it for power-amplifier matching networks or other RF paths with appreciable heat generation. Build a thermal path model that includes the copper, vias, carrier and interface materials rather than assigning all cooling performance to the dielectric.
- A thinner substrate can shorten the heat path but also changes impedance geometry. Evaluate RF width, current density and thermal resistance together before selecting core thickness.
Thickness and copper options
Select the listed core thickness against both RF geometry and thermal-path requirements; standard entries include 10, 20, 30 and 60 mil.
The datasheet lists ED foil and discusses low-profile performance; identify the exact copper configuration in loss comparisons.
Fabrication considerations
- Ask the fabricator to qualify drilling and surface preparation for the filled PTFE construction. If the board is bonded to a metal carrier, define the adhesive thickness and contact-area requirements separately from the laminate thickness.
Application fit
- RF power amplifiers
- High-power matching
- Thermally demanding microwave circuits
Limits and substitution checks
- The 1.44 W/(m·K) datasheet value uses ASTM C518 at 80°C; it is not directly interchangeable with a different method or direction on another grade. HTC does not establish a safe power rating or a finished device junction temperature without the full heat path.