Rogers’ RO4000® series laminates (RO4003C, RO4350B, and RO4835) are engineered for high-frequency applications. These materials offer low loss, controlled dielectric constants, and excellent thermal and mechanical stability. This guide provides quick reference points for processing these laminates effectively.

1. Material Characteristics

Property	RO4003C	RO4350B	RO4835
Dielectric Constant (Dk)	3.38 ± 0.05	3.48 ± 0.05	3.33 ± 0.05
Dissipation Factor (Df)	0.0027 @ 10 GHz	0.0037 @ 10 GHz	0.0035 @ 10 GHz
Thermal Conductivity (W/m·K)	0.62	0.69	0.66
Glass Transition Temp. (°C)	>280 (no Tg defined)	>280 (no Tg defined)	>280 (no Tg defined)

2. Pre-Lamination Preparation

1. Material Conditioning:
   • Pre-bake laminates at 120°C–150°C for 1–2 hours to remove absorbed moisture.
   • Cool to room temperature before processing to avoid warping.
2. Surface Preparation:
   • Clean copper surfaces with an alkaline cleaner or microetch for optimal adhesion.
   • Avoid over-etching, as it may affect the bond strength.

3. Drilling Recommendations

1. Drill Parameters:
   • Drill bit speed: 70,000–150,000 RPM.
   • Chip load: 0.001–0.003 in/rev (25–75 µm/rev).
   • Retract rate: 500–800 IPM (12.7–20.3 m/min).
2. Stack Height:
   • Limit to 0.200 in (5.08 mm) for better precision and reduced burring.
3. Post-Drilling Cleaning:
   • Use plasma or chemical desmear to clean resin residues.

4. Etching and Imaging

1. Copper Etching:
   • Use standard PCB etching processes with mild etchants like ferric chloride or ammonium persulfate.
   • Control etching rates to prevent undercutting.
2. Imaging:
   • Employ dry film photoresist compatible with the laminate surface.
   • Expose and develop under standard parameters.

5. Lamination Process

1. Stack-Up Design:
   • Balance the stack to prevent bowing and warping.
   • Use Rogers prepreg materials or compatible bondply for multilayer construction.
2. Lamination Conditions:
   • Temperature: 425°F–475°F (218°C–246°C).
   • Pressure: 300–500 psi (20.7–34.5 bar).
   • Duration: Hold at temperature for 60 minutes for proper curing.
3. Cool Down:
   • Cool under pressure to below 100°F (38°C) to minimize residual stresses.

6. Soldering and Assembly

1. Soldering:
   • Laminates are compatible with lead-free and traditional soldering processes.
   • Use a controlled reflow profile with a peak temperature of 245°C–260°C.
2. Component Attachment:
   • Conductive epoxy can be used for heat-sensitive components.
   • Ensure good thermal contact for high-power devices.
3. Thermal Management:
   • Incorporate thermal vias or heat sinks as required.

7. Testing and Inspection

1. Electrical Testing:
   • Perform impedance checks to verify trace dimensions and dielectric performance.
2. Dimensional Inspection:
   • Measure for warping or shrinkage post-lamination. Adjust process parameters if required.
3. Thermal Shock and Cycling:
   • Test reliability under operational conditions to ensure long-term stability.

8. Storage and Handling

1. Storage Conditions:
   • Store laminates in a controlled environment at 20°C–25°C with <50% relative humidity.
2. Handling:
   • Use gloves and avoid direct contact with laminate surfaces to prevent contamination.

The RO4000 series laminates provide superior performance for high-frequency and RF applications when processed correctly. By following these guidelines, fabricators can achieve consistent results and optimal circuit performance.