RO4830 Plus is a woven-glass-free thermoset laminate intended for thin millimeter-wave RF layers. Its reinforcement choice is a meaningful distinction from original RO4830 and from glass-reinforced RO4000 grades. The product datasheet ties its Design Dk to 77 GHz and lists a 5 mil VLP-copper construction.
Material system
Ceramic-filled thermoset; woven-glass-free construction
Technical properties
| Property | Reported value | Conditions / source |
|---|---|---|
| Process dielectric constant | 3.00 ± 0.04 | Typical; 10 GHz, 23°C/50% RH; IPC-TM-650 2.5.5.5 clamped stripline; direction is not separately recorded here. Source |
| Design dielectric constant | 3.03 | Typical; 77 GHz, microstrip differential phase length method. Do not relabel this observation as a 10 GHz measurement. Source |
| Dissipation factor | 0.0015 | Typical; 10 GHz, 23°C/50% RH; IPC-TM-650 2.5.5.5; direction is not separately recorded here. Source |
| Thermal conductivity | 0.5 W/(m·K) | Typical, through thickness; ASTM D5470. The product table does not state test temperature. Source |
| CTE, X axis | 46 ppm/°C | Typical; -40°C to 140°C, IPC-TM-650 2.4.41. This differs from the selector's generic temperature heading. Source |
| CTE, Y axis | 47 ppm/°C | Typical; -40°C to 140°C, IPC-TM-650 2.4.41. This differs from the selector's generic temperature heading. Source |
| CTE, Z axis | 56 ppm/°C | Typical; -40°C to 140°C, IPC-TM-650 2.4.41. This differs from the selector's generic temperature heading. Source |
| Thermal coefficient of dielectric constant | -54 ppm/°C | Typical; -50°C to 150°C, IPC-TM-650 2.5.5.5 (modified temperature measurement); 10 GHz. Source |
| Water absorption | 0.02 % | Typical; D48/50, IPC-TM-650 2.6.2.1. Source |
| Density | 1.64 g/cm³ | Typical; C-24/23/50, 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 an RF cap layer in a hybrid radar board when homogeneous dielectric structure and compatible thermoset fabrication are important. Simulate the actual cap-layer thickness, solder mask exclusions and antenna surroundings together.
- Compare it with RO3003G2 using measured or modelled transmission lines of equal geometry and foil condition. A lower quoted Df alone cannot decide the complete radar feed loss.
Thickness and copper options
The current datasheet lists a 5 mil (0.13 mm) dielectric with ±0.5 mil tolerance; confirm any other configuration separately.
The standard offering uses 18 µm VLP ED copper. Low roughness is a feature of that ordered construction.
Fabrication considerations
- The datasheet describes compatibility with RO4400 bonding material and conventional glass-epoxy processes. The fabricator should still validate laser drilling, registration and the complete hybrid lamination sequence for the selected FR4 stack and copper density.
Application fit
- 77–81 GHz radar RF layers
- Patch antennas
- Radar feed networks
Limits and substitution checks
- The supplied 77 GHz Design Dk must not become a generic 10 GHz value. Its CTE measurements also use a different temperature interval from the broad selector heading. Material-level radar positioning is not evidence that a finished sensor meets automotive qualification or radar-range requirements.