RO4360G2™ laminates from Rogers Corporation are high-frequency materials with a dielectric constant (Dk) of 6.15 ± 0.15, designed for advanced RF and microwave applications. These laminates are compatible with FR-4 processing methods, making them a cost-effective solution for high-performance circuits. The following guidelines help optimize fabrication processes to ensure reliability and performance.
Material Properties Overview
| Property | Typical Value | Test Method |
|---|---|---|
| Dielectric Constant (Dk) | 6.15 ± 0.15 | IPC-TM-650 2.5.5.5 @ 10 GHz |
| Dissipation Factor (Df) | 0.0038 @ 10 GHz | IPC-TM-650 2.5.5.5 |
| Glass Transition Temperature (Tg) | >280°C | TMA |
| Thermal Conductivity | 0.8 W/m·K | ASTM E1952 |
| Peel Strength | 1.0 N/mm | IPC-TM-650 2.4.8 |
| Moisture Absorption | <0.1% | IPC-TM-650 2.6.2.1 |
Fabrication Guidelines
1. Drilling
- Drill Bits: Use high-speed carbide drill bits designed for PTFE and ceramic-filled laminates.
- Parameters:
- Speed: 150,000–200,000 RPM
- Feed Rate: 2–3 mil/rev
- Retract Rate: 500–600 IPM
- Hole Preparation:
- After drilling, perform plasma desmear or chemical cleaning to ensure good copper adhesion for plated through holes (PTHs).
- Back-up and entry materials are recommended to minimize burrs and maintain clean hole walls.
2. Lamination
- Prepreg Compatibility: Use RO4450F™ prepregs for multilayer board constructions to ensure material compatibility.
- Pressure and Heat:
- Pressure: 200–400 psi
- Temperature: 425–450°F (220–230°C)
- Time: Maintain peak temperature for at least 60 minutes.
- Ensure uniform pressure distribution to avoid warping or uneven bonding.
3. Etching
- Standard copper etching processes are suitable.
- Tight process controls are necessary to achieve consistent line widths, especially for RF/microwave circuits with fine geometries.
4. Solder Mask Application
- Use solder masks compatible with high-frequency laminates.
- Ensure thorough surface cleaning before application to promote adhesion.
5. Soldering
- RO4360G2 laminates are compatible with lead-free soldering processes.
- Controlled reflow profiles are necessary to avoid exceeding the material’s glass transition temperature (Tg).
6. Surface Finishing
- Compatible with a variety of surface finishes, including:
- Electroless Nickel Immersion Gold (ENIG)
- Immersion Tin or Silver
- Organic Solderability Preservative (OSP)
Thermal Management Considerations
- RO4360G2 laminates offer good thermal conductivity (0.8 W/m·K), but high-power designs may require additional heat sinks or thermal vias for enhanced heat dissipation.
Best Practices
- Material Storage:
- Store laminates in a cool, dry environment to prevent moisture absorption.
- Process Validation:
- Test fabrication parameters on sample boards to ensure process compatibility and minimize errors.
- Dimensional Stability:
- Use compensation factors for dimensional changes during processing, especially for high-density circuits.
- Handling Precautions:
- Avoid bending or flexing the laminates to prevent cracking or delamination.
Applications
- High-density RF circuits.
- Power amplifiers in telecommunications.
- Aerospace and automotive radar systems.
- High-frequency filters and couplers.
RO4360G2™ laminates deliver exceptional performance for RF and microwave applications. By adhering to these fabrication guidelines, manufacturers can achieve reliable results, optimized circuit performance, and efficient production processes.
