RO4835 High Frequency PCB 60mil Thick For Point-To-Point Microwave With ENIG

Today, we will be discussing a type of oxidation-resistant PCB called RO4835 high-frequency PCB.

All thermoset laminate materials, including FR-4, undergo oxidation over time and with temperature exposure. This oxidation can lead to slight increases in the dielectric constant and dissipation factor of the circuit substrate, affecting its performance. To address this issue, Rogers has developed the RO4835 laminate, which offers improved stability at high temperatures and is more resistant to oxidation compared to traditional hydrocarbon-based materials.

Let's take a closer look at the key properties of RO4835.

RO4835 Typical Properties:

- Process DK: The process dielectric constant of RO4835 is 3.48±0.05 at 10 GHz and 23°C. The design dielectric constant is 3.66 for a broader frequency range of 8-40 GHz.

- Dissipation Factor: The dissipation factor is 0.0037 at 10 GHz and 23°C, indicating low signal loss.

- Thermal Coefficient of Dielectric Constant (TCDk): RO4835 has a TCDk of +50 ppm/°C over a wide temperature range (-100°C to 150°C), making it suitable for variable temperature environments.

- Electrical Strength: It exhibits a high electrical strength of 30.2 kV/mm (755 V/mil), indicating good insulation performance.

- Mechanical Properties: RO4835 demonstrates a tensile modulus of 7780 MPa (1128 kpsi), tensile strength of 136 MPa (19.7 kpsi), and flexural strength of 186 MPa (27 kpsi), providing mechanical stability.

- Dimensional Stability: It offers excellent dimensional stability with a shift of less than 0.5 mm/m (mils/inch) after etching and exposure at 150°C.

- Coefficient of Thermal Expansion (CTE): The CTE values are 10 ppm/°C (X-direction), 12 ppm/°C (Y-direction), and 31 ppm/°C (Z-direction) within the range of -55°C to 288°C, ensuring reliable plated through holes.

- High Tg and Decomposition Temperature: RO4835 has a high glass transition temperature (Tg) greater than 280°C and a decomposition temperature (Td) as high as 390°C, making it suitable for high-temperature applications.

- Thermal Conductivity: It has a thermal conductivity of 0.66 W/m/K at 80°C, aiding in heat dissipation.

- Moisture Absorption: RO4835 exhibits a very low moisture absorption rate of 0.05% after 48 hours of immersion at 50°C, making it suitable for use in humid environments.

- Flammability and Lead-Free Compatibility: It is UL 94 V-0 rated for flammability and compatible with lead-free processes.

PCB Capability (RO4835):

We offer various PCB options using RO4835 laminate:

- Layer Counts: We provide single-sided, double-sided, multi-layer, and hybrid PCB options.

- Copper Options: Choose between ED copper and reverse treated copper.

- Dielectric Thickness: Options for ED copper include 6.6 mils, 10 mils, 20 mils, 30 mils, and 60 mils. For reverse treated copper, options include 4 mils, 7.3 mils, 10.7 mils, 20.7 mils, 30.7 mils, and 60.7 mils.

- Copper Weight: We offer copper weights of 1oz (35µm) and 2oz (70µm) for track lines.

- Maximum PCB Size: The maximum size we provide is 400mm x 500mm, accommodating various design requirements.

- Solder Mask Colors: Choose from a range of colors, including green, black, blue, yellow, red, and purple.

- Surface Finish Options: We provide options such as immersion gold, HASL, immersion silver, immersion tin, bare copper, OSP, and pure gold for pads protection.

Conclusion:

RO4835 high-frequency PCBs offer excellent stability and performance in high-temperature environments. With low loss, high electrical strength, dimensional stability, and lead-free compatibility, RO4835 laminates provide a cost-effective solution for high-frequency applications. These PCBs find applications in automotive radars and sensors, power amplifiers, phased array radars, and various RF components.

Thank you for joining us today. We hope you found this information valuable. Stay tuned for more updates, and we'll see you next time.