RO3035 offers an intermediate dielectric constant within the ceramic-filled RO3000 PTFE family. It can be a useful design point when RO3003 gives inconveniently large distributed structures but RO3006 would demand excessive miniaturization or temperature compensation. Its value is the combination of electrical and processing properties, rather than a universal frequency boundary.
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; thickness direction. 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 | 0.0015 | Typical, 10 GHz, 23°C; IPC-TM-650 2.5.5.5; thickness direction. Source |
| Thermal conductivity | 0.5 W/(m·K) | Typical; ASTM D5470, 50°C, through-thickness direction. Source |
| CTE, X axis | 17 ppm/°C | Typical; -55°C to 288°C, IPC-TM-650 2.4.41; average expansion over the interval, not necessarily linear. Source |
| CTE, Y axis | 17 ppm/°C | Typical; -55°C to 288°C, IPC-TM-650 2.4.41; average expansion over the interval, not necessarily linear. Source |
| CTE, Z axis | 24 ppm/°C | Typical; -55°C to 288°C, IPC-TM-650 2.4.41; average expansion over the interval, not necessarily linear. Source |
| Thermal coefficient of dielectric constant | -45 ppm/°C | Typical; -50°C to 150°C, IPC-TM-650 2.5.5.5 (modified temperature measurement); 10 GHz. Source |
| Water absorption | 0.04 % | Typical; D48/50, IPC-TM-650 2.6.2.1. Source |
| Density | 2.1 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
- Compare it with RO3003 at the same core thickness when adjusting line widths or resonator size. Use Design Dk in an appropriate model and check whether the loss saving or geometry benefit survives a complete copper-loss calculation.
- For an amplifier network, evaluate conductor current density and thermal paths separately. The moderate dielectric constant does not directly determine power handling or allowable junction temperature.
Thickness and copper options
Select the RO3035 core configuration from the product datasheet; a family name alone does not establish the thickness tolerance.
Specify copper weight and treatment separately from dielectric grade, especially for long lines and thin cores.
Fabrication considerations
- Have the fabricator confirm the RO3000 process for the chosen filler and thickness. If the board includes a bonded RF layer, identify the bondply dielectric and actual pressed thickness because it can change effective permittivity at discontinuities.
Application fit
- Microwave matching networks
- Moderate-Dk RF feeds
- Distributed filters
Limits and substitution checks
- RO3035 is not the same construction as RT/duroid 6035HTC despite a similar process Dk. The latter's thermal emphasis does not transfer to RO3035. Temperature dependence and mechanical properties also need review when replacing a material on a tuned RF platform.