6-Layer RO4350B & IT180A Hybrid PCB 1.6mm Thick Blind Via & Edge Plating High

Product Specification

This custom 6-layer hybrid high-frequency PCB adopts a premium mixed dielectric stackup combining Rogers RO4350B and IT180A materials, delivering balanced low-loss high-frequency performance and rigid mechanical stability. The layered structure features 0.254mm RO4350B substrates on both the top and bottom sides, paired with a 0.55mm IT180A core dielectric and 0.075mm IT180A prepreg bonding layers, forming a standard finished board thickness of 1.6mm. It applies asymmetric copper configuration with 1.42oz finished outer copper layers and 1oz finished inner copper layers, meeting high-current conduction and precise signal transmission requirements for RF circuits.

This PCB adopts double-sided green solder mask with white silkscreen for clear circuit identification and reliable anti-solder protection, supplemented by high-quality immersion gold surface finishing to enhance oxidation resistance and soldering stability. Professionally customized with advanced blind via technology for L1-L2 and L3-L6 interlayer connections, it optimizes circuit density and signal routing efficiency while avoiding through-hole interference. Equipped with full edge plating treatment, the board gains improved structural integrity, electromagnetic shielding performance and wear resistance. Sized at 110mm × 110mm per piece, this high-reliability hybrid PCB is ideal for high-frequency communication, microwave sensing and precision RF equipment applications.

PCB Specifications

High-Frequency Copper Foil Types & Performance Characteristics

Copper foil acts as a foundational conductive component for high-frequency and microwave PCBs, greatly influencing signal transmission efficiency, interlayer bonding stability, and long-term operational durability. Rogers high-frequency dielectric substrates are compatible with a diverse range of copper foil variants, each featuring unique structural traits and electrical performance. Proper copper foil selection based on circuit design and application environments is essential for maximizing signal integrity and overall PCB reliability. Below are the most commonly used copper foil types for high-frequency PCB fabrication:

Standard Electrodeposited (ED) Copper Foil

Electrodeposited copper foil is fabricated by depositing pure copper ions onto a rotating titanium drum under controlled DC electrical conditions. This process creates an asymmetric structure with a sleek, smooth drum-facing surface and a coarse matte surface on the opposite side. Copper thickness can be precisely adjusted by modifying drum rotation speed, supporting flexible weight customization. Both surfaces receive specialized finishing treatments to strengthen interlayer adhesion with dielectric materials and improve oxidation resistance. These enhancements prevent copper tarnishing and ensure stable lamination quality, making ED copper foil a reliable option for conventional high-frequency circuit designs.

Rolled Copper Foil

Rolled copper foil is produced via repeated cold rolling processes that compress pure copper billets into uniform, ultra-thin copper sheets. Its surface flatness and smoothness are determined by rolling machine precision and processing parameters. Compared to standard ED copper, rolled copper boasts a denser, more homogeneous internal structure, delivering exceptional ductility, mechanical flexibility, and fatigue resistance. With minimal conductor loss and stable physical properties, it is widely adopted for high-reliability high-frequency PCBs that require consistent bending endurance and precise signal transmission.

Resistive Copper Foil

Developed based on standard ED copper foil, resistive copper foil undergoes professional modification with metal or alloy coating applied to its matte surface, followed by nickel particle roughening treatment. This forms a stable resistive layer on the foil surface, enabling accurate impedance tuning for high-frequency circuits. Tailored for precision RF systems and signal attenuation circuits that demand strict resistance consistency, this copper foil type effectively stabilizes circuit impedance and minimizes signal interference in sophisticated high-frequency modules.

Reverse Treated (RTF) ED Copper Foil

Reverse treated ED copper foil features surface enhancement treatment on the naturally smooth drum side, unlike conventional ED copper. A thin functional coating micro-roughens the smooth surface, significantly boosting bonding affinity with dielectric substrates and improving corrosion resistance. During lamination, the treated roughened side bonds tightly with the dielectric core, while the original matte side retains ideal roughness for photoresist adhesion without additional chemical or mechanical processing. This design effectively lowers delamination risks and conductor loss, perfectly suiting high-precision multilayer high-frequency PCB applications.

LoPro Copper Foil

LoPro copper foil is an upgraded iteration of reverse-treated ED copper, integrated with a premium adhesive reinforcement layer on the treated surface. This physical bonding layer further optimizes interfacial integration between copper foil and dielectric materials, delivering ultra-low profile topography and superior lamination stability. Fully compatible with Rogers RO4000 series high-frequency substrates, LoPro copper effectively reduces high-frequency signal loss and enhances passive intermodulation (PIM) performance. It serves as the premium copper solution for high-end microwave, satellite communication, and precision RF equipment.

Crystalline Structure Differences of Various Copper Foils

The internal crystal structure fundamentally differentiates the performance of electrodeposited and rolled copper foil. ED copper crystals grow vertically along the foil’s Z-axis, forming a regular fence-like vertical crystal arrangement. This structure features clear and long crystal boundaries perpendicular to the foil plane, providing basic conductivity and adhesion for conventional high-frequency circuits. In contrast, the cold rolling process crushes and refines the internal grains of rolled copper, forming small, irregular spherical crystals that are nearly parallel to the foil plane. The refined and uniform crystal structure endows rolled copper with better structural stability, lower signal attenuation and stronger fatigue resistance, more suitable for high-end high-frequency and high-speed circuit applications with rigorous performance requirements.