RO4450F is a ceramic-filled, glass-reinforced thermoset bonding material for RO4000 multilayers. It supplies both resin for encapsulating inner-layer copper and a dielectric spacing between conductors. The material's nominal properties are useful only when tied to the final pressed construction and the chosen core stack.
Material system
Ceramic-filled hydrocarbon thermoset prepreg with woven glass
Technical properties
| Property | Reported value | Conditions / source |
|---|---|---|
| Process dielectric constant | 3.52 ± 0.05 | Typical; 10 GHz, 23°C/50% RH; IPC-TM-650 2.5.5.5 clamped stripline; direction is not separately recorded here. Source |
| Dissipation factor | 0.004 | Typical; 10 GHz, 23°C/50% RH; IPC-TM-650 2.5.5.5; direction is not separately recorded here. Source |
| Thermal conductivity | 0.65 W/(m·K) | Typical; ASTM D5470, 80°C, through-thickness direction. Source |
| Water absorption | 0.04 % | Typical; D24/23, IPC-TM-650 2.6.2.1; current product sheet. 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 a RO4000 multilayer where a documented compatible thermoset prepreg and familiar lamination approach fit the design. Determine the required fill from copper thickness, pattern density and layer topology before deciding the ply count.
- For a stripline layer, model the core and bonding regions separately when their dielectric constants differ. The adhesive's contribution cannot be inferred from the adjacent RO4350B core name.
Thickness and copper options
Order the exact RO4450F prepreg construction and use the fabricator's predicted and measured pressed thickness for the copper pattern.
The bond material is unclad. CU4000 and CU4000 LoPro are separately specified foil options for compatible foil lamination.
Fabrication considerations
- Use the applicable RO4400 processing guidance and discuss resin flow, surface treatment and sequential-lamination exposure with the fabricator. Where outer foil is laminated, the CU4000/CU4000 LoPro compatibility document is a useful source for the foil choice.
Application fit
- RO4000 multilayers
- Hybrid RF stackups
- Foil-laminated RF boards
Limits and substitution checks
- The current datasheet moisture observation differs from the selector and uses a different conditioning regime. Neither a family compatibility statement nor a typical Dk guarantees void-free bonding or a particular final spacing. A press-temperature summary is not a validated complete lamination cycle.