RO4350B+FR4 HDI PCB

Description

Hybrid boards are essential in modern high-performance PCB designs, especially in high-frequency applications. Combining RO4350B and FR4 materials is a common solution in complex PCB designs as it compensates for the limitations of each material, balancing cost-efficiency with outstanding performance. This document provides an in-depth explanation of the main features, manufacturing processes, challenges, and application scenarios of the 6-layer blind via RO4350B + FR4 hybrid board.
1. Characteristics of RO4350B and FR4 Materials
RO4350B Material:
RO4350B, manufactured by Rogers Corporation, is primarily used for high-frequency applications. Its main features include:
Low Dielectric Loss: RO4350B significantly reduces signal transmission losses compared to traditional FR4 material, ensuring excellent signal integrity.
Stable Dielectric Constant (Dk): It has an outstanding and stable dielectric constant of 3.48, making it suitable for high-speed and high-frequency designs.
Low Moisture Absorption: RO4350B has low moisture absorption and high thermal resistance, making it ideal for harsh environments.
FR4 Material:
FR4 is a traditional epoxy-based substrate that is more cost-effective than RO4350B. Its key features include:
Reliable Mechanical Performance: FR4 provides excellent structural support, making it ideal for multi-layer hybrid constructions.
Ease of Processing: FR4 is compatible with traditional PCB manufacturing processes and can be seamlessly integrated into hybrid designs.
Cost-Efficiency: FR4 is a cost-effective solution for large-scale PCB production.
2. Manufacturing Steps for RO4350B + FR4 Hybrid Boards
When manufacturing hybrid boards, RO4350B and FR4 require precise processing to balance thermal and mechanical properties. The key steps include:
Step 1: Material Preparation and Layer Alignment:
Protect the RO4350B material during initial processing to preserve its thermal and electrical characteristics.
Integrate FR4 layers for structural stability.
Step 2: Blind Via Fabrication:
Blind vias are drilled and plated to connect inner and outer layers. The process ensures minimal impedance loss, essential for high-speed designs.
Step 3: Multi-Layer Lamination:
Hybrid lamination combines RO4350B and FR4 under controlled pressure and temperature conditions, ensuring uniform integration without warpage or delamination.
3. Key Manufacturing Challenges
Material Compatibility: Balancing the thermal and mechanical properties of RO4350B and FR4 during lamination is critical.
Blind Via Fabrication: Precise control of via drilling and plating is essential to maintain signal integrity.
Thermal Management: Managing heat dissipation in hybrid boards requires careful material selection and design optimization.
4. Applications and Future Prospects
Hybrid boards are widely used in aerospace, telecommunications, and high-speed computing applications. Their ability to combine cost-efficiency with superior performance makes them a preferred choice for advanced electronic designs. As technology continues to evolve, the demand for high-performance hybrid boards like RO4350B + FR4 will continue to grow, driving innovation in PCB manufacturing.